As the human inundation continues, pouring from one poor country into another, India's concern sharply rises. Those who doubt Indian sincerity in wanting a solution to the tragedy in East Pakistan seem to forget the refugees are costing the government US$3 million a day just to provide minimal food, shelter and medical care.

Foreign relief organisations have called this perhaps the biggest single relief operation ever tackled, and the seven million could become 10 by the year's end. For India, humanitarian considerations aside, it is a major catastrophe. The refugees have created an emergency which has taken priority over everything else. The magnitude of the task is overwhelming, the demands on the Indian exchequer and human resources, unprecedented.

For India to meet them is "unreasonable", for these are not Indians but nationals of a foreign country. It is not India's responsibility, but there is no escape. The restoration of "normal conditions" in East Pakistan is a remote dream, whatever Yahya Khan claims or Islamabad officials have persuaded themselves. The victims of West Pakistan's repression of the eastern wing are India's burden - perhaps for years.

Bongaon subdivision in the politically explosive state of West Bengal illustrates the effect of the great influx. Refugees started pouring into this area on March 27 - the day the Pakistani army began "to restore normality" in what was supposed to be originally a 72- hour operation - and the flow has continued ever since.

The first camp in Bongaon opened on March 30. The subdivision covers 320 square miles and along two sides shares a border with East Pakistan. The 1961 census put the population at 350,000. Now there are 29 camps housing exactly the same number of people. In addition more than 100,000 refugees are living with friends or relatives, and there is a "floating" population of more than 50,000. New arrivals are in the region of 35,000 a day.

The official specification in the camps allows 20 square feet a head, but 15 people are occupying the space intended for 10. Many camps are just long lines of barracks - bamboo structures with roofs of thatch or tarpaulin, common dormitories with many families living without any privacy. But even these camps are full. Here, as in most of West Bengal, it is difficult to find non-agricultural land for camp sites. The normal population density is very high: 1,500 per square mile. Today it is 5-6,000 per square mile. There is no more space.

This is low-lying land, mostly jute and paddy fields, without drainage conduits. Where there is no standing water, there is marsh. Under such conditions efforts at sanitation are almost futile. In some places separate latrines have been built, in others trenches dug. But in the monsoon, the water and human congestion create a gigantic hygiene problem. Danger of polluted water and resultant diseases is constant.

Compared to West Bengal, the Tripura and Assam camps are luxurious. The influx has been lower and the current flow of arrivals is put at 4-5,000. The first few weeks were as chaotic as in West Bengal, but the newly constructed camps are well designed, built on healthy ground, with plenty of space between buildings. Assam camps even provide for a separate kitchen for each family in the allotted space.

But there are other serious problems. Tripura, Assam and Meghalaya are eastern border states, not readily accessible from the rest of the country. Transporting building materials, food supplies, even the refugees themselves, is a major difficulty. Roads are narrow, only a few have hard surfaces and none are built for regular heavy truck traffic. Camps are far from the towns because land near them is unavailable, and towns are connected only by precarious communications with railheads and airfields.

In Tripura 200 tons of food has to be brought in daily even under normal conditions. The state's population of 1.55 million has been almost doubled by the refugee influx of 1.12 million. Food requirements are now 660 tons a day. Local officials describe their situation as a "truck to mouth existence" - foodstocks are nil and monsoon conditions generate frequent landslides, which can cut the roads at any time. The railhead is 125 miles from Agartala, even further from other refugee camp points. There is a chronic shortage of trucks which the state is trying desperately to meet, and an airlift, also dependent on the weather, can only bring in about 60 tons daily. Nobody seems to know what will happen if the supply line is cut.

To reduce the daily requirements to 300 tons, the refugee ration has already been cut by 50%. Further cuts are impossible for nutritional reasons. In Bengal each refugee receives 800 grammes a day of foodstuffs, cereals, vegetables and pulses, with a small cash payment for extras. This costs the government one rupee a day. Rations elsewhere are approximately the same. This is a minimal amount, but the government cannot afford even this, and already there is resentment because millions of Indians live on less.

The refugees need much else besides - clothes, utensils, supplementary foods, soap and kerosene. But the Indian government cannot even attempt any relief of this kind. Private and foreign agencies are trying to fill the gap but they still have a long way to go. However milk powder - the most important supplementary food for children, the sick and prenatal and postnatal cases - is being provided by them and distributed in 50% of the West Bengal camps and in many others.

Distribution is not always efficient and the chief victims are children. But it is no easy matter to organise distribution, registration and rations on such a vast scale, when the administrative apparatus is already strained beyond capacity, and when the number of people to be served increases every hour. Despite bottlenecks, lack of experienced relief personnel and other drawbacks, India has done a magnificent job under extraordinary circumstances.

Foreign assistance, shockingly little in the beginning, is now a steady flow, but although the materials provided - for shelter, medical care, extra food - are all vitally important, they only complement the massive national effort. India is paying for Yahya Khan's terror.

Medical care, preventive and curative, requires full medical teams. One doctor per 6,000 persons has been provided, according to officials. Bangla Desh doctors are included in this figure. Again this is the barest minimum. Cholera is under control, thanks to a massive inoculation campaign and high-speed injections along with large supplies of saline solution. Whenever there is a heavy influx of refugees, the number of cases goes up; 90% of the new arrivals bring the disease with them. Still, the fear of huge epidemics is gone. But other threats - tuberculosis, pneumonia, intestinal diseases, all aggravated by malnutrition and weakness - are just around the corner. In the more settled camps, conditions of health have improved. Asked if he was worried about the death-rate in the Tripura camps, a local official smiled: "I should say I am more worried about the birthrate."

But Indians are asking when the influx will end. Reports of imminent famine conditions in East Bengal are well founded. Those who were doing relief work in last year's cyclone-torn areas say near-famine conditions were forecast there even before the present crisis. With the winter harvest untended and the new crop unsown, a famine of cruel intensity is likely. Well over 500,000 persons are already said to be on the move in search of food. Their inevitable destination seems to be India. Conservative estimates in India of 10 million refugees within a few months are giving place to the terrifying picture of a possible 15 million.

Care of the present numbers of "evacuees" - as the Indian government insists on calling them officially - is achieved at the cost of Indian development. Even normal programmes in fields such as education, health, family planning are suffering. If the number of refugees remains fairly static, which is highly unlikely, the total expenditure on them for this financial year will be at least 20% of the entire Indian budget. The refugees have already been here five months, and so far only a tiny handful have gone back. India is already drawing on its foodstocks, especially rice, to meet their needs. The economy has been seriously disrupted and the five-year plan will inevitably be affected.

In places where refugees are concentrated, local administration has time for nothing else. These are all backward districts. Many are in a state of intense political tension partly due to the violent activities of the Maoist Naxalites. Schools and colleges, filled with refugees, have not opened in these areas, a dangerous situation when the young are the main targets for Naxalite persuasion. All development work has stopped. Planning for urban improvements in Calcutta, a priority project, has been postponed. "Our plans for a mini green revolution have all been shelved," says a Tripura administrator ruefully.

The federal government is bending over backwards to preserve what many Indians feels is an illusion: that the refugees are temporary evacuees, who will certainly return to their country. For this reason no schools are being opened in the camps. Only "education centres" keep the children occupied. Certain human problems cannot be postponed. Orphans, who must be cared for, are being looked after in "temporary" orphanages, widowed women and women who are alone in- "temporary" homes.

"Our refugee provision in every respect is for six months," explains Tripura's relief secretary. "Our local population is friendly because we have assured them the refugees are only here for six months. This is tribal country. Local people go in for shifting cultivation and are very jealous of their land rights. If they think these people are here permanently, we may have serious trouble." Locals are already complaining because prices have gone up since the refugees have been forced to buy in the open market after the ration cut. In Assam it is the same story, and where the refugees are not installed in camps, prices have risen by 30%. In West Bengal people are resentful because schools have not reopened.

There is friction when the refugees help themselves to fruit from trees, or break off kindling. In areas near Calcutta, some refugees have started undercutting the local wage rates, thus taking jobs from residents. As the influx increases more of ' this will happen and, small irritations may culminate in serious trouble. There are also fears that the continuing influx may push refugees in camps near Calcutta into the congested, tension-gripped metropolis - in which case, say observers: "Calcutta will explode."

India's security problems have been aggravated by the influx. In Assam, fears lest the large number of Moslem refugees upset the population balance, always an ultra- sensitive point in this important border state, have already erupted into a riot in the state capital of Shillong. Recent reports of alleged saboteurs caught in Tripura lend credence to rumours that Pakistan agents may be infiltrating the area in the guise of refugees, as a potential fifth column in case of an Indo-Pakistan conflict.

In Agartala, the sound of Pakistani mortars falling into Indian territory can be heard almost every day. Indian civilians as well as soldiers are being killed or wounded all along the increasingly sensitive border. If the refugees keep coming and if there is no way for them to return, war - even with the calming influence of the Indo-Soviet security treaty - may become India's only way to solve its dilemma.

The refugees, India has rightly insisted, will only go back when there is a genuine political solution in Pakistan. Perhaps eventually Yahya will be persuaded by the great powers that, however distasteful he may find it, he must make his peace with the eastern wing. And this can only mean negotiations with the Awami' League - before the communists take the political lead in building up guerilla resistance. But so far Islamabad shows no signs of modifying its political stance, or its military tactics - despite reports of potential trouble in West Pakistan.

Meanwhile the Mukti Fauj is keeping the Pakistan army on the alert, cutting important communication lines, capturing arms, exploding bombs in Dacca and killing soldiers and collaborators. The military forces sent in have not been able to establish control over the country. Guerillas penetrate the heart of Dacca and several times over the past weeks saboteurs have plunged the city into darkness. It is even said you can drive across the border from India to Dacca, spend the night in the Intercontinental hotel and leave very early in the morning - although recently even the hotel has not been immune from attack. The reason: the army reportedly retires to barracks at nightfall, and only emerges at dawn.

Eyewitnesses report the Mukti Fauj is increasingly better organised and claim more and more young men are joining it. An intensive recruitment drive is on in the camps to enlist all men and boys from the age of 14 up. Indian Defence Minister Jagjivan Ram said recently that Yahya Khan's bellicosity towards India was a thermometer indicating the success of the Mukti Fauj. But guerilla warfare never brings rapid solutions, and the "freedom fighters" are pitted against formidable opponents.

Dedicated young faces sing the Bangla Desh national anthem in the soft Tripura twilight in a little refugee camp run by a Christian mission. If Yahya refuses to negotiate with the Awami League, and convicts Mujib, these youngsters will grow up - probably at India's expense - to fight for their freedom. But it is hard to see how India can bear the burden; impossible to predict what it will mean for its future. The sacrifice of Prime Minister Indira Gandhi's "Gharibi Hatao" (remove poverty) programme - on which she gained her great parliamentary majority this spring - will be crucial enough. In addition, there is the political dilemma. The numbers of the deprived and restless in India are growing and, by diverting so much of its already so inadequate means to succouring the victims of another country's repression, India risks revolt among its own nationals. West Bengal is possibly the worst place in the world to be called on to support a humanitarian burden which would weigh heavily on even the United States.