CALCUTTA, India, Oct. 11— Under heavy security, several special freight trains carrying military supplies now arrive here every day. The arms are reported to be for the Bengali guerrillas who are fighting for East Pakistan's independence and who seem to be preparing to step up their activities against the Pakistani army.

On the guerrilla side, the crucial question is how far India is willing to go in support of the independence movement. So far the Indians have been providing sanctuary, training and a certain amount of arms.

The political leaders of the six-month‐old independence struggle, who are based in Calcutta, have been complaining that the Indians are not giving them enough arms to equip all their trained men.

Moreover, India, largely because of the restraining advice of her closest ally, the Soviet Union, has not granted de jure recognition to the government of Bangle Desh (Bengal Nation), the name given to East Pakistan by the independence movement. The thinking behind that restraint has been that recognition might precipitate a war with Pakistan.

The flow of heavily guarded freight trains into Calcutta indicates that India has agreed to give the guerrillas more arms, but it does not necessarily mean that she is prepared to give them what they really want—logistic support and air cover for a frontal push into East Pakistan to seize control of a chunk of territory.

Even though Indian troops would not be involved, such a move would clearly be regarded by Pakistan as an act of war.

Meanwhile, an air of suspense continues to grow between the Indian and Pakistani armies, on both the eastern and western borders of divided Pakistan. Reliable reports indicate that both sides have reinforced their troops on the always sensitive frontiers.

Troop Moves Observed

This correspondent has observed Indian troop movements along the border with East Pakistan. Near one border point, at Petrapole, Indian regulars were training with recoilless rifles, often used against tanks.

There are many rumors about the possibility of another Indian‐Pakistani war—a brief but bloody one was fought in 1965 —but there is no strong evidence that it is imminent, and the troop movements may be elaborate psychological warfare.

In recent days the Indian press has been full of reports of a Pakistani military build‐up, of civilian evacuation from some Pakistani border areas and of war hysteria and a hate-India campaign in Pakistan. Correspondingly, the Pakistani press has been heavy with reports of an Indian build‐up and of Indian border provocations such as shelling.

Furthermore, security has been tightened around the camps that hold the Bengali refugees, who have fled the Pakistani military repression in East Pakistan. Indian officials say that Pakistani agents have infiltrated the camps.

An Indian news agency, Press Trust of India, reported that the authorities had imposed a blackout and air‐raid measures at the extensive oil refineries and depots in Assam, an eastern border state.

Whether those pieces add up to anything, it would be logical, now that the annual monsoon rains and floods are just about over, for both the Pakistani Army and the Bengali guerrillas to increase their activities.

As for India, the social and economic pressures of the refugees are mounting. Official estimate that over nine million have poured across the border and that the influx continues at about 30,000 a day (the Pakistanis put the total at much less).

Is there a breaking point, the foreign diplomats are asking, point at which the Indians decide that the strains are so great that they must take direct military action to stop the refugee flow?

Whatever the two governments do, all reports here indicate that the guerrillas are about to open a stepped‐up offensive. They have already delivered some hard blows. They have severed—and kept severed —the main rail line, many key roads and innumerable bridges, and they constantly blow up crucial power installations. Since August guerrilla frogmen have been attacking ships in East Pakistan's harbors and have damaged or sunk at least a dozen. As a result British lines have suspended traffic to East Pakistan.

Guerrillas Claim Big Toll

The guerrillas claim the killing of 20,000 to 30,000 Pakistani soldiers; although that is considered an exaggeration, the casualties are believed to be considerable. No figures are available on guerrilla casualties.

There are estimated to be 80,000 Pakistani soldiers in East Pakistan, plus about 10,000 hastily trained non‐Bengali home guardsmen.

Estimates of the number of guerrillas range from 50,000 to 100,000, many thousands of them trained since the Pakistani Army launched its attack against the independence movement in March. The hard core of professionals consists of more than 15,000 men who defected from the East Pakistan Rifles, a paramilitary border patrol force, and the East Bengal Regiment, a regular army unit.

Many of the guerrilla training camps and base areas are on the Indian side of the border, but a growing number of Bengalis have been operating from areas in East Pakistan adjoining the border.

Some recruits are being trained as guerrillas and others as regulars. “We need both,” a high official said, “because the guerrillas can only hurt and weaken and soften. We need a force that can hold territory.