CALCUTTA, India, Dec. 10—Indian troops crossed a major river obstacle today and were poised for a final drive on Dacca, the capital and bastion of the Pakistani forces in East Pakistan, according to Indian military officials.

The Indian radio said the troops were already advancing on Dacca after crossing the wide Meghna River at Ashuganj, only about 40 miles northeast of the capital. But a spokesman for the army's Eastern Command said at a briefing here tonight that the Indian forces were consolidating at their new bridgehead near Bhairab Bazar, on the Meghna's western bank, and had not yet begun the drive.

The spokesman added, however, that “from here, Dacca is directly threatened without any major obstruction.”

On Water and by Air

He said that the Indian crossing at Ashuganj, where the retreating Pakistanis blew up big railway bridge, was being carried out with river steamers and helicopters.

Some 30,000 of the 70,000 to 80,000 Pakistani troops who had been trying to put down the Bengali insurrection in East Pakistan are believed to be in the Dacca area. Their situation seems even more hopeless than that of the scattered pockets in the outer reaches of the Indian‐encircled region.

After only seven days of war brought on by the dispute over the situation of the Bengalis, the Indians have gained complete air, sea and land superiority in the east. Every Pakistani fighter aircraft in East Pakistan is said to have been shot down. The river and sea escape routes are blocked by the Indian Navy and Air Force, while the Indian Army squeezes the largest concentration of the Pakistanis inexorably toward Dacca and the Bay of Bengal.

Surrender Call Ignored

India has called on the Pakistanis to surrender, but not many are doing so.

At a briefing in New Delhi a senior spokesman said that isolated Pakistani garrisons were receiving orders to hold out. He said Dacca was telling them: “We wish to gain time. Something big may happen.”

In a jocular vein, the spokesman said that India believed the “something big” was “the escape of senior officers” from East Pakistan.

On the western front over 1,000 miles away, the Pakistanis launched another big attack in the Chhamb area of southwestern Kashmir, but otherwise there was no major action in what has become a fairly static situation.

The Pakistani attack in Indian territory began before dawn and was still going on at sunset, Indian officials said. Pakistani forces won Chhamb Town, about 10 miles from the border, in a thrust three days ago and were trying to push farther in. The Indian officials, who said the Pakistanis were getting effective air cover, described Indian casualties for the first time as heavy. Pakistani losses were even heavier, they added.

With the situation deteriorating for Pakistan, foreign nationals in both wings of the country have become jittery. The evacuation of foreigners began today, with several hundred of them — mostly Britons and Canadians — being airlifted out of Karachi under the protection of a temporary air cease‐fire observed by both countries.

Under a similar cease‐fire agreement tomorrow, three British transports are to take 185 Britons and perhaps other foreigners out of beleaguered Dacca.

India has insisted that the planes stop in Calcutta going into and coming out of Dacca, maintaining that control of the planes' route in this manner is the only way she can guarantee their safety. Diplomatic observers here think that by checking the planes the Indians are simply trying to make certain that no Pakistani leaders escape from East Pakistan.

Truce Expires Tonight

It is believed that the British planes will carry out 46 United Nations employes in Dacca, but it is not clear whether they will also evacuate the approximately 300 other foreigners in Dacca. If these are to be evacuated, it will have to be done quickly for the cease‐fire runs out at 6 P.M. tomorrow.

Reliable sources here said that the Dacca airfield, severely damaged by Indian bombing, was being repaired well enough to allow the transports, C‐130 s, which do not require much landing or take‐off distance, to make it.

A footnote to the Dacca evacuation is that United Nations officials now say that the Canadian plane that was reported damaged by Indian planes when it tried to land a few days ago “wasn't damaged a bit.” The pilot flew on to Bangkok. The Indians — angrily denying charges of unknown origin that their planes had attacked the evacuation craft — said he had probably seen some smoke from previous raids, panicked and flown off.

Reports from Dacca say that excitement is mounting among the bitterly anti‐Pakistani Bengali population as the Indian Army gets nearer and nearer. The Pakistanis have agreed that the hospitals in the city and the Intercontinental Hotel, where foreigners and newsmen stay, will be neutral zones.

Denials by the Pakistanis

While preparations for siege go on, Pakistan continues to deny that her forces have suffered major setbacks or lost any of the big cities in East Pakistan even though foreign newsmen have visited the Indian‐held city of Jessore, which had been a Pakistani stronghold.

A Pakistani spokesman in Rawalpindi was quoted today as saying that “we are winning the war” and that Pakistani troops could hold out indefinitely in the East.

“They'll still be denying any setbacks when they're swimming in the Bay of Bengal,” an Indian military source commented.

The Dacca radio fell silent and the Indians maintained that their planes had knocked out its transmitters.

The Indians report that many Pakistani solders are changing into civilian clothes and trying to escape through the countryside or in boats. As a result the Indian Navy, which has warned all foreign ships to stay out of, the area, is stopping all merchant vessels in the Bay of Bengal.

The Indians have seized or attacked some vessels that were apparently going about perfectly innocent tasks. Eight small ships are tied up in Calcutta harbor.

Six Danish ships, all 400‐ton coastal craft under charter to the Gulf Shipping Company of Pakistan, were seized Monday while on their way to Barisal carrying milk products. Each had a sign on its bridge in black two‐foot letters: “Carrying Humanitarian Relief Under United Nations Auspices.”

India's explanation for seizing such ships is that there might be contraband aboard that could be used by Pakistan in the war effort.

On the West Pakistani coast, on the Arabian Sea, an Indian naval force bombarded Karachi Harbor the night before last, Indian spokesmen said. The oil refinery complex at Kemani was set ablaze, they said.

Along the East Pakistani coast, Indian planes and ships continued to pound the major river and sea ports. Officials say scores of boats have been destroyed, several carrying troops.

A small Pakistani force of troops trying to reach the Khulna‐Chalna port area from Jessore has been encircled by Indian troops, a military spokesman here said. He said three companies of Pakistanis, or about 500 men, were involved. They are reportedly fighting hard to hold back the Indians; one reason for their tenacity may be that they have their families with them—some thousand women and children.

A spokesman in Delhi said that Indian troops had bypassed several Pakistani garrisons in towns as part of an attempt to “avoid avoidable damage” to assets of Bangle Desh (Bengal Nation), the name given to East Pakistan by the Bengali insurgents who have been fighting for independence for eight months.