CALCUTTA, India, Dec. 12—Pakistan relented today on letting foreigners leave Dacca, and the evacuees arrived in India saying that the Bengali population was fleeing the East Pakistani capital in droves as Indian troops moved in on the city.

As the Bengalis pour out of Dacca, the evacuees said, Biharis and other non‐Bengalis—the minority groups who have collaborated with the Pakistani Army during its eight‐and‐a-half month repression of the Bengalis—are pouring in, carrying the arms given them by the army.

“If the Pakistanis are serious about their last‐ditch talk,” said one of the 420 foreigners who flew out to Calcutta today, “they're going to burn the city down rather than surrender.”

The evacuees also described the “almost continuous” raids by Indian planes since the war began nine days ago, the round‐the‐clock curfew that was imposed yesterday, the firing by the army‐trained home guards at lighted windows during the nightly blackouts, the blowing up of the United States Information Service building yesterday by an unidentified man, and the increased restrictions on the reporting and movements of foreign newsmen, all of whom are under near‐confinement at the Hotel Intercontinental.

International Pressure Applied

The nervous foreigners got out of Dacca today only after heavy international pressure, particularly from Britain, persuaded the Pakistanis during the night to agree to the airlift by three British C‐130 Hercules transports.

The airlift had been blocked yesterday morning when, despite earlier Pakistani acceptance of the evacuation plan, the Dacca control tower turned back the first aircraft from Calcutta, saying that no plane that came from India could land there. The Indians had insisted that the planes stop in Calcutta on the way in and on the way out to make sure that no military contraband was being taken in and that no senior Pakistani officials had slipped out on the aircraft.

Two earlier attempts at evacuation by a Canadian plane last week were unsuccessful because of firing and bombing along the plane's route to Dacca.

Many diplomats here thought that the Pakistanis had blocked the airlift yesterday because they wanted the foreigners as potential hostages, perhaps to dissuade the Indians from attacking Dacca.

Pressure on Pakistan

Last night, however, the British and others, it is understood, impressed on the Pakistanis that if they stuck to this course, they could expect no assistance in the days ahead, diplomatic or otherwise, from the many countries whose nationals were trapped in the city.

Of the 420 foreigners who flew out of Dacca today, about 180 were British, 120 American and the rest divided among a number of nationalities.

Most were private citizens with business in East Pakistan. The diplomatic personnel of the consulates in Dacca, or at least skeleton staffs, are staying on. The diplomatic staff of the United States Consulate is remaining, but some officials of the mission of the Agency for International Development have been sent out. The American wives and children were evacuated eight months ago, when West Pakistani soldiers began the crackdown on the Bengalis in an attempt to crush their autonomy movement.

The three Royal Air Force transports made a total of four trips to and from Dacca before the temporary air cease‐fire agreed upon by India and Pakistan expired at 2 P.M.

The four flights could not accommodate everyone who wanted to leave. About 25 persons, all unmarried men, were said to have been left behind.

Most of the evacuees flew to Singapore, where the planes are based, after an inspection stop in Calcutta. The other evacuees are staying temporarily in Calcutta.

Orphanage Reported Hit

The evacuees, all of whom asked to remain unidentified either because of their official positions or for business reasons, said that since Dec. 4, the day after Pakistan attacked Indian air fields, Indian fighter‐bombers had been carrying out “almost continuous” raids on the Dacca airfield and military cantonment and on Narayanganj, a large river port about 10 miles south of Dacca where some fuel tanks have been blown up.

They said that the night raids, which usually began at 2 A.M. and lasted two and half hours, were the most frightening because they were “pretty erratic.”

Another raid a few nights ago hit an orphanage, the evacuees said. Some reports put the death toll at over 100.

The evacuees said that the Dacca curfew, which had been 5 P.M. to 5 A.M., was extended yesterday to 24 hours a day.

They said that there had been several rumors about the total curfew. One was that the Pakistani troops wanted to round up people sympathetic to the Bengali independence cause and that the curfew would make this easier because it would keep people at home.

Another was that the purpose of the curfew was to “slow down” the panic and the Night on Bengalis out of the city.

The flood of non‐Bengalis into the city, carrying arms out of fear of the local Bengali population, represents a climax of years of antagonism between them and the Bengalis.

Resented by Bengali

It is estimated that of East Pakistan's population of 75 million, perhaps two million are non‐Bengalis. They are mostly Moslems from what are now the Indian states of Bihar, Orissa and Uttar Pradesh who came to East Pakistan when the subcontinent was carved up in 1947. They are usually all referred to as Biharis and they have always identified with West Pakistan and shared the West Pakistanis' racial disdain for the Bengalis.

The Bengalis resent them not only for this but also because many Biharis are merchants and are more prosperous than the Bengalis. When the West Pakistani troops began cracking down on the Bengalis last March, the Biharis joined in the repression and killing.

Most observers believe that the Bengalis will now seek their revenge on the Biharis. This is why the Biharis are pouring into Dacca, to take refuge in the last army stronghold.

The majority of diplomats feel that the only way to avert a bloodbath in East Pakistan now is for the Pakistani Army there to surrender to India and seek safe conduct back to West, Pakistan for the troops and some kind of protection or safe conduct for Biharis.

Irregulars Roam Streets

But the Biharis do not seem to be trying to improve their image. The evacuees reported that Bihari irregulars roamed the streets of Dacca during the blackout firing at any window, that showed a crack of light.

One evacuee said that even with Indian troops advancing, Pakistan soldiers as of a few days ago were still burning villages and killing the residents in some areas.

In an incident in Dacca yesterday, the evacuees reported that a man carrying a Sten gun had walked into the large U.S.I.S. building, told everyone to clear out and, when they did, planted a bomb and ran off. The explosion, a few moments later, blew debris all over the road and caused heavy structural damage, making the building unusable, according to the reports.