CALCUTTA, India, Nov. 20— India is approaching a war footing as the battles with Pakistani troops along the East Pakistan border become bigger, more frequent and more intense.

Details are scarce because this military activity has been accompanied by an Indian ban on travel by foreign newsmen to border areas.

“We're doing things we just can't let you see,” said one official. “The border is hot. All around.”

The Government continues to deny publicly that Indian troops are crossing the border or doing anything but responding to what it calls Pakistani provocations. But despite heavy security, reports are getting out. From them, it has become clear that the Indian strategy, is to keep a large number of the Pakistani troops in East Pakistan pinned down along the 1,350‐mile border while the Bengali guerrilla army fighting for the independence of East Pakistan steps up its tempo against the thinly spread Pakistani forces in the interior. The Pakistanis are believed to have 70,000 to 80,000 troops in East Pakistan.

One frequent pattern of battle seems to be as follows:

The guerrillas, some based on Indian soil, push into East Pakistan and engage the Pakistani troops, nearly all of whom are from West Pakistan. he guerrillas then pull back toward India, pursued by the Pakistanis. When the Pakistanis approach the border or cross it, the Indian troops open fire, drive them back and sometimes follow them into fast Pakistan.

In this way, territory inside East Pakistan is seized and turned into guerrilla enclaves. According to unconfirmed reports in some areas Indian troops have dug in on the East Pakistani side.

The Indians, according to the available evidence, are hoping to accomplish their objective—a friendly, independent East Pakistan—without a full‐scale war. They are gambling that the Pakistanis will soon be forced to abandon their military occupation of East Pakistan because they lack enough troops or equipment for a total war.

Nonetheless, the Indians say they are prepared for war if it comes. One theory is that the Pakistanis might attack in the West, slicing into Kashmir— where the two countries have fought twice before—to seize a piece of territory in retribution for the loss of East Pakistan.

In speeding up their time table, the Indians are said to be thinking in terms of a victory in two or three months Without a total war. Such a victory, they feel, would enable most of the millions of East Pakistani refugees who have fled to India to return to a secure, homeland.

Casualties Called Light

Indian sources say that their casualties have been “light.” But reports indicate that in one battle alone—near Kamalpur on the eastern side of East Pakistan—the Indians lost about 80 men.

The Pakistanis, according to Indian sources, have lost at least 6,000 men, with 12,000 more wounded, since March when the Pakistani troops moved into East Pakistan to try to crush the Bengali autonomy movement. Most of the Pakistani casualties are said to have been inflicted by the Bengali guerrilla insurgents, who call themselves the Mukti Bahini (Liberation Forces).

The guerrillas say they have 100,000 men in the field. Al though the force is poorly armed and trained, it is clearly much stronger than it was eight months ago.

The guerrillas are now operating boldly in the interior; even in the capital city of Dacca. They are reported am bushing army patrols, killing collaborators, mining roads and destroying power stations and bridges.

Indian assistance in arms, training and border sanctuary has been increasing steadily and in the border areas the two forces seem to be operating al most as one.

Some foreign diplomats here think the step‐up in Indian activity may well produce a war, because it leaves the Pakistani President, Agha Mohammad Yahya Khan, no way to extricate himself from a losing fight in East Pakistan and still hold his political power in West Pakistan.

President Yahya was warned that if the guerrillas seize a large part of East Pakistan, he will consider that an act of war by India and will declare war on her.

Indian officials acknowledge that their course of action makes war a possibility, but they have apparently decided that, barring a dramatic last minute change of mind by Pakistan's rulers, there is no other way to ease the political, social and economic pressures that the Pakistani military action in East Pakistan has put on India and which India considers intolerable.