CALCUTTA, India, Nov. 22—A major offensive by Bengali insurgents, aided by Indian troops, is apparently under way against the Pakistani Army on the western side of East Pakistan, according to reports reaching Calcutta.

Capture of the city of Jessore seems to be a key initial objective, and heavy fighting was reported not far from the city, which is about 20 miles inside East Pakistan and 85 miles southwest of the regional capital, Dacca.

First‐hand details are nonexistent and information of any kind remains sketchy because of tightening security here and the rule that forbids foreign newsmen to travel to sensitive areas on the border.

Guerrilla Gain Reported

But there were indications that the Bengali forces fighting for the independence of East Pakistan were pushing Pakistani troops back for the first time since the Pakistanis moved last March to try to crush the Bengali autonomy movement and ousted the guerrillas from the province's cities.

At that time most of the guerrillas retreated into India, where the Government has given them arms and training.

The Indian Government's radio reported this morning that the Bengali guerrillas were battling the Pakistanis in the Jessore area and pushing them back, The radio report said the insurgents had knocked out several Pakistani tanks which were termed American‐made.

A foreign newsman who managed to drive to the Indian border town of Bangaon, which is 45 miles northeast of here on the road to Jessore, said that during the hour he stayed in the area he could hear intermittent artillery and small arms fire in the distance from the direction of East Pakistan.

Local residents told him, he said, that the military had imposed a curfew on the area several days ago—from 4 P.M. to 5 A.M.—and that during curfew hours, large convoys of trucks carrying troops were passing through on the way to the border and returning empty. The local people said they thought that the troops were Indian but said that they could not be sure in the dark whether they might not have been Bengali guerrillas.

Pakistan's Government radio charged yesterday that two Indian infantry brigades and an armored regiment had attacked in the Jessore district and had been beaten back. According to Pakistan, 90 Indian soldiers were killed and 160 wounded, with Pakistani forces suffering only 4 dead and 6 wounded.

Pakistanis List Units

The Pakistanis said that seven Indian tanks were damaged and ‘identified the Indian infantry units as the Jammu and Kashmir Rifles and the 350th Infantry Brigade of the First Sikh Regiment. The Pakistani broadcast said that 5,000 shells had been fired in the battle and that it was the biggest intrusion by the Indians in the border confrontation, which has been ‘intensifying in the last several. days.

The Indians denied involvement in or even knowledge of the battle, which apparently took place yesterday.

An Indian spokesman, at a briefing in New Delhi this evening, said: “We have seen reports of the battle between Pakistani and Mukti Bahini [Bengali name for liberation forces] troops in Jessore. We have no information about this. We have also seen the radio broadcast of Pakistan on this. We deny having launched any major offensive.

“As you know, Pakistan has been describing Mukti Bahini as Indian agents. We don't know the details. We have no knowledge of Mukti Bahini having any tanks, The report about the presence of Indian tanks there is absolutely false. Indian troops have strict orders not to cross the border.”

The spokesman said, in answer to a question, that while the border with West Pakistan had been “relatively quiet,” the border with East Pakistan “appears to be heating up in some places.”

India Charges Intrusion

He said that four Pakistani jets had intruded into Indian air space today at a point about 65 miles northeast: of Calcutta. Indian planes fired on them, he said, but scored no hits as the Pakistani jets flew back across the border.

This morning, Indian Army officials abruptly canceled a scheduled trip by eight foreign journalists to what had been, until now, a non-sensitive border town named Taki, opposite East Pakistan's Khulna District. The officials said “some fighting” was going on.

The foreign newsman who made it to the border area, however, had received his permit in New Delhi and was not part of the guided tour.

The newsman visited a Mukti Bahini headquarters on Indian soil near Taki. The commander there, Major Jill‐Ed, said that most of the road and railroad to Jessore were now under the control of his troops. The major, who denied Indian involvement, said that a Mukti Bahini force of 8,000 to 12,000 men was moving into position to attack the Pakistani force in Jessore.

Reports from the northwest corner of East Pakistan indicated that Pakistani troops there were slowly falling back before the advancing guerrillas, without engaging in a serious fight. According to these reports, the guerrillas had pushed more than 20 miles into East Pakistan.