KARACHI, PAKISTAN,-The chief of Pakistan's military intelligence service portrayed his nation today as facing large Indian military forces along the frontiers and said he could not discount the possibility of war.

Maj.. Gen. Mohammad Akbar Khan told a group of foreign news correspondents that India had moved two and one-half divisions of men - a division has about 30,000 men - mountain and airborne brigades, fighter, bomber and air transport units and her Navy to supplement Indian forces already close to Pakistan's border.

SEES IT AS A MANEUVER

He said that with the Indian Army strength regularly around East Pakistan's borders, India's total army strength there was more than five divisions with a sixth in readiness nearby.

Yesterday, General Akbar Khan said the Indian Air Force placed six fields near East Pakistan on war alert, to which Pakistan responded by ordering an alert of her own.

"We think this is just a maneuver on their part," the general said, "but at tomes like this, such things have a way of escalating." West Pakistan, which is separated from its eastern wing by about 1,000 miles of Indian territory, continues to face Indian obstacles to the transportation of men and equipment to the East Pakistan has been denied the right to fly over Indian territory, and as a result, civilian and military aircraft must fly far out of their way.

A new unit of Soviet-built ground-to-air missiles operating on India's southern tip the general said, has begun to practice firing to as far as 123 miles from the Indian coast. He said that this forced Pakistan's aircraft to fly even farther south.

More immediately threatening, General Akbar Khan asserted were at least 10 battalions of Indian border security forces that he said had infiltrated into East Pakistan in cooperation with local separatist forces.

ELECTION OF THE ROOT

The Pakistani crisis is an outgrowth of Pakistan's elections for the National Assembly, held in December. The Awami League, an East Pakistani party led by Sheikh Mujibur Rahman, won a commanding majority and it was expected that the party majority would write a constitution - the assembly's task that would bring about government by the Easterners.

However, the President, Gen. Agha Mohammad Yahya Khan, postponed the convening of the assembly, which had been set for March 3. The Awami League began a move for local autonomy, but negotiations between General Yahya and Sheikh Mujib broke down. On March 25, the Pakistani Army began its efforts to put down the autonomy move, warfare broke out and the East Pakistanis declared their area the independent country of Bangla Desh - Bengal Nation.

UNDERMINING CHARGED

The Indian Government has expressed support for the Bengali separatists, and the leaders of the secessionists, who have based their government in a border area, are believed to take periodic refuge in India, aside from their hostility as overwhelmingly Moslem and predominantly Hindu countries carved out of what was once British India, Pakistan and India have fought brief but bloody wars over territory.

A strong statement Issued today by the Pakistani Government said: The root cause of the Indo-Pakistan trouble is that India has never really accepted the fact of Pakistan. India has spared no effort to undermine Pakistan.

General Akbar Khan said, "Short of open war, India has taken everything possible available to it against us. We cannot rule out the possibility of war now, although we have no wish for it. In any case, we are ready."

The general said that East Pakistani paramilitary forces, police and officials had largely joined in the secessionist fight and conceded that of the Pakistanis serving within Pakistan's Army, about 10 per cent had defected to the secessionists.

FEARS OF INFILTRATORS

But he said that resistance had virtually disappeared and charged that the main danger now was continued Indian military infiltration.

The general denied that the Pakistan Army had killed large numbers of women and children, as charged by the Bengali separatists.

"We are a proud army with a great fighting tradition in many wars," he said. "Where we met rifle, machine-gun and mortar fire, we answered with fire. But we do not go around killing women and children."

General Akbar Khan denied that large numbers of civilian Pakistani refugees had fled to India.

"According to signals we intercepted two days ago," he said, "about 37,000 refugees, nearly all of whom are miscreants and common criminals, have crossed into India. India which has a great many hungry people, claims there are one million refugees over there in order to get international help in feeding them."