Calcutta. Under cover of an intensive security blackout Indian forces appear to have launched a concerted offensive against East Pakistan along the entire West Bengal border from Rangpur in the north to Taki in the south, 51 miles from Calcutta. Senior Indian officers said yesterday that they expected a total Pakistan collapse within seven days. They said the Pakistan Army seemed to have lost all its fight, and was retreating in the concentrated pockets along 1 400-mile front.

Normally, the gains are said to have been made by the Mukti Fouj guerrillas of Bangladesh. But the degree of support provided by India is now clearly so great that this is nothing more than a quibble. Last night, heaviest fighting was said to be in the southern sector where hundreds of guerrillas, heavily backed by Indian armour and artillery, were fighting for control of the key town of Jessore, where there is a major Pakistan garrison. Staff officers expect Jessore, with its vital airfield, to fall within four days.

Now facing an apparent debacle, the Pakistan Army has concentrated in Jessore cantonment, three miles from the town itself, for a last ditch fight. With guerrillas in effective control of the surrounding countryside they have no route to escape. The start of what is in effect if not in name the major Indian offensive was signaled earlier in the week when Indian 106 mm anti¬yank guns knocked out 13 light Pakistan tanks. Mrs. Gandhi told Parliament that this was only a local action, and that the Indians had fired in self-defence. A further sign of what was really afoot came on Wednesday when official sources in New Delhi stated that Indian units now had permission “to cross the frontier in self-defence.”

ELABORATE MOVES OF CONCEALMENT

The wording was fairly transparent. Indian Government sources emphasised that it was not a euphemism for allowing local commanders to smash their way into Pakistan’s entrenched positions and advance into East Pakistan. But this in fact, according to highly reliable sources, is what is happening. The Indians have made elaborate arrangements to conceal the facts of the newly-launched campaign and prevent accurate determination of development.

A permit system makes it impossible for most foreign observers to go anywhere out of Calcutta, and certainly not sufficiently close to the border.

Large stretches of territory have been designated “sensitive” and entry is barred. Indian journalists also are forbidden to go to the frontier. Indian newspapers which have come to know the facts are exercising self¬-censorship.

4 P.M. CURFEW

A strict curfew has been imposed in border areas every day of this week from 4 p.m. until dawn All civilian movement has been prohibited. People living in these areas spoke yesterday of hearing extensive vehicle movements every night. The roads and by-ways are pitted with the marks of tank tracks, and the presence of hundreds of commandeered lorries is evidence of the scale of the support operation.

INTERNAL ISSUE, SAYS DELHI

It is now clear that during the past week India has moved large numbers of tanks and quantities of field artillery to the border, only a few hundred yards from entrenched Pakistan positions. The Army is working in the closest possible cooperation with the Mukti Fouj guerrillas, giving them light and heavy artillery cover and full logistic support including communications, field hospitals and food supplies. Maintaining what is now essentially a fiction, that the Mukti Fouj is separate, the actual taking of Pakistan territory is being left to the guerrillas, though probably guided by Indian “advisers.”

India is sticking to the political claim that events in East Pakistan are entirely “an internal issue” between the guerrillas and the Pakistan Army. But in effect the Mukti Fouj and the might of the Indian Army are now one effective fighting unit, and India can be said to be engaged in something close to an all-out war with Pakistan in this area. The Indian army is supremely confident that it can deal Pakistan a death blow. Officers at all levels are brimful with confidence. This is not unjustifiable. Indian intelligence sources consider that because of its mounting internal problems in both wings Pakistan has become too enfeebled to put much of a fight.

POLITICAL REIN

The key to the entire situation has been held by Mrs. Gandhi and her closest advisers in New Delhi. Although the Army has been “raring to go” for weeks, it has been kept on a tight political rein. Mrs. Gandhi’s apparent aim has been to resolve the crisis and ensure the return of nearly ten million refugees to East Pakistan without resort to an all-out or direct conflict with Pakistan. But to accelerate the process India has given support to the guerrillas which has now escalated to the point of all out commitment. India still maintains the formal stance of not being directly involved.

India’s political assessment would seem to be that Pakistan is a rotten apple, eaten away from within, and ready to fall, now so weak that India can afford to take risks. The danger still must be that despite the evident seriousness of his situation, President Yahya Khan may decide to hit back along the Western front, in the Punjab and Kashmir.