KARACHI, PAKISTAN, JULY 16 -- Pakistani Prime Minister Mohammed Khan Junejo said tonight that India and not Afghanistan may have been behind the two car bombings Tuesday that killed at least 72 persons here.

Junejo, who cut short a state visit to Japan to rush back to Karachi, appeared to be distancing himself from President Mohammed Zia ul-Haq, who said yesterday that he believed the bombing was related to Pakistan's support for Afghan refugees and that recent bombings were "only the beginning" of a severe test for this country.

The two bomb blasts, and earlier ones in Rawalpindi, Lahore, and Peshawar, triggered widespread criticism of the government's policy of welcoming some 3 million Afghan refugees and of its unacknowledged support for Afghan guerrillas fighting Soviet and Kabul forces in Afghanistan.

By pointing a finger at India, Junejo revived animosities with Pakistan's bitter foe to the east but also appeared to be attempting to diffuse political pressure building over the government's Afghan policy.

The differing public postures taken by the two top leaders reflect Pakistan's complex foreign policy and its evolving domestic politics. Zia has been president for a decade but is taking a less public role as Junejo struggles to establish himself as an elected prime minister. Despite elaborate efforts to display public harmony, strains between the two occasionally show.

Junejo said at a press conference tonight that officials believe the bombings confined to the frontier region with Afghanistan are connected to Pakistan's Afghan policy.

Bombings in other regions, such as in this port city of 7 million, however, "forced us to look in the other direction," toward India, Junejo said. He added that his government knows of 17 training centers in India for saboteurs who are to carry out attacks in Pakistan, and said he has made these charges to Indian Prime Minister Rajiv Gandhi.

Junejo's charges were similar to India's repeated claim that Sikhs carrying out terrorist acts receive weapons and training in Pakistan.

The armed forces of the two South Asian countries, which have fought three major wars in four decades, were on high alert this past winter during maneuvers on each side of the border. Since then, however, the climate of distrust has appeared to moderate.

"Pakistan will not compromise on its principled stand on Afghanistan," said Junejo. "We didn't invite Afghan refugees here. They came because of Soviet troops."