CALCUTTA, India, June 6— The cholera epidemic among Pakistani refugees in West Ben gal now threatens to spread to this city of six million people. At least 60 refugees are re ported to have died of the dis ease in the city or its outskirts in the last two days.

A hundred miles away, in the district of Nadia, the cholera death toll exceeds 5,000, ac cording to unofficial estimates.

Many of the refugees are making for Calcutta, an official spokesman said. Efforts are being made to stop them, but the official said that it was impossible to keep them from trick ling through.

Some 40,000 refugees have been encamped for four days near Calcutta's international airport, 10 miles from the city. At least 50 refugees reportedly have died there.

The authorities yesterday sealed off one refugee camp known as the Sahara, and barred new refugees, most of whom moved on toward Calcutta.

Many stopped at a mud‐filled marsh close to populous east ern Calcutta. There were 600 refugees there last Wednesday, but today it was estimated that 10,000 refugees were huddled beneath umbrellas and inside huge concrete pipes. They have no same drinking water, and there have been 10 deaths there.

Jainal Abedin, Health Minister of West Bengal State, said yesterday that the situation was beyond the means of the state and out of control. He appealed to the central Government for immediate supplies of anticholera vaccine and saline injections to treat cholera victims, who suffer dehydration.

Refugees began crossing the border into India after the Pakistani Army moved in March to crush the autonomy movement in East Pakistan.