Cambodians forced from their homes into rural communes by the Pol Pot government were moving back to their villages and towns yesterday, according to the new government in Phnom Penh, which continued its successful military drive with key Vietnamese support.

The new government was recognized by Laos and Vietnam, indicating that Hanoi was moving quickly to consolidate what has long been a dream of the Vietnamese leadership -- an Indochina confederation under Hanoi's domination.

Soviet President Leonid Brezhnev offered his congratulations to the new leadership, in line with the Kremlin's support for Vietnam, and East German Premier Willi Stoph said his country would cooperate closely with the government of Heng Samrin.

Analysts in Bangkok said that the Vietnamese air force, accompanying ground forces, had launched a series of attacks against pockets of resistance bypassed in the two-week drive on Phnom Penh, according to news agency reports.

One attack strayed over the border into Thailand. Two warplanes, believed to be either Mig21s or Mig19s, dropped three bombs between two Thai military installations along this border. No injuries were reported.

Meanwhile, speculation mounted over the fate of Premier Pol Pot and Deputy Premier Ieng Sary. There were persistent reports in Bangkok that Pol Pot may have been killed, according to news agencies, but Prince Norodom Sihanouk, en route from Peking to New York to plead the case of the ousted government before the United Nations said he had been in radio contact with both men.

In the weeks prior to the lightning Vietnamese-backed strike that toppled Pol Pot, he said repeatedly that his forces were prepared to abandon the cities and move into the countryside for a campaign of guerrilla warfare.

Since the military drive against him was so swift and successful, however, analysts have wondered whether his forces had time to move to jungle and mountain redoubts.

There has been similar speculation over the fate of an estimated 19,000 Chinese still believed to be inside Cambodia. Officials in Washington noted yesterday that there had been no reports of Chinese getting out of the country, except for several hundred who crossed the border into Thailand on Monday.

The prospects for waging guerrilla war "will depend on how much the military got up, what kind of communications they can set up and how much sentiment the new government can instill by rolling back the harsh measures enacted by Pol Pot's government," one analyst said.

Reports from Bangkok yesterday indicated that the forces of the old government appeared to be in control of areas of western Cambodia adjacent to Thailand, although artillery fire could be heard from the Thai border town of Aranyaprathet.

Intelligence sources in Bangkok said Pol Pot forces appeared to control the towns of Siem Reap and Battambang, although there was fighting around nearby Tonle Sap Lake.

The issue of which Cambodian government could gain the allegiance of the people was shaping up as a critical one. The harsh, repressive measures of the Pol Pot government, estimated to have resulted in hundreds of thousands of deaths, apparently left it with little support in the countryside as the insurgents and Vietnamese launched their most recent attack.

Analysts here, however, questioned whether the presence of Vietnamese forces, long antagonists of the Cambodians, might not rebound against the new government over the long run.

It was against this background that the new government reported yesterday that people in the northeastern part of the country around Kompong Cham were moving in thousands of bullock carts back to their homes after their enforced exile under Pol Pot.

The report, among the first from Phnom Penh since the takeover, said military units were escorting the villagers.

One of the first pronouncements of the provisional government established by Heng Samrin and his colleagues was their intention to allow people to return to their homes and to restore other traditional practices outlawed under the radical practices adopted by Pol Pot.

Meanwhile, the Association of Southeast Asian Nations, five noncommunist countries in the region, called on Cambodia and Vietnam to halt the fighting and agreed to support a call for a U.N. Security Council meeting on the Cambodian situation.

A meeting of foreign ministers from the five countries -- Thailand, Malaysia, Singapore, Indonesia and the Philippines -- was called for Friday in Bangkok.