Two weeks after Army troops rolled into this stronghold of overthrown president Ali Nasser Mohammed and found evidence of what they said were wholesale massacres of his political opponents, white flags of surrender still flew this week over many dwellings. Residents apparently fear reprisals despite insistence by the new regime that there will be none.

Abyan province, to which Mohammed and his Politburo allies fled after the failure of their Jan. 13 attempt to eliminate their political rivals in South Yemen's Marxist government, is firmly in the control of forces loyal to provisional President Haidar Abu Bakr Attas.

But authorities acknowledged that in the wake of more than 200 slayings here in the days immediately following the abortive strike against the opposition, many civilians were braced for a counterwave of terror.

Mohammed Ali Qarhi, acting governor of Abyan, told western journalists visiting the overthrown president's primary constituency that no reprisals by the victorious side had taken place. But neither he nor other leading figures in the People's Socialist Party said how many supporters of Mohammed had been arrested or taken into custody. One militiaman said some of those arrested had been killed.

Mohammed and his chief aides reportedly fled Abyan before Army forces arrived in this town 40 miles east of Aden, and officials said they apparently are out of the country.

In Moudiya, a village in Mohammed's home district, white flags flew over many houses, but the local police commander, Mohammed Saleh Mabrash, said that the residents had been "completely terrified by Ali Nasser's propaganda."

Mabrash said some "misled" people had left the village at Mohammed's request to fight for him at Zinjibar. One of the "misled" villagers produced by authorities to talk to reporters -- Ali Ahmed Mansour -- said he and 15 other residents went to Zinjibar, but he said he did not fight the troops who entered the city on Jan. 20.

Mansour, who was carrying a Kalashnikov assault rifle, said that when he arrived here he realized that Mohammed and his supporters had not been the targets of a coup attempt but rather were trying to eliminate political opponents. He said he immediately deserted the pro-Mohammed forces and returned to his village.

Mansour said he did not know what became of the pro-Mohammed supporters rounded up by the government forces. But another People's Militia member said, "When they (the people) realized that Ali Nasser had failed, yes, some of the armed elements killed them if they found them."

Mohammed, a Marxist who angered hard-line Communists by his attempts to improve relations with conservative Arab states in the Persian Gulf area, reportedly ordered his personal troops to kill his political rivals, including his chief critic, Abdul Fatah Ismail, at a special Politburo meeting Jan. 13.

Several of Mohammed's foes were machine-gunned to death and others, including Ismail, vanished and were presumed killed, but survivors succeeded in rallying sufficient armed forces to put down his attempt to seize full control. Attas, who was abroad at the time, flew to Moscow for consultations and then returned to South Yemen as provisional president.

Details and accounts of the alleged massacres in mid-January continue to emerge, presenting a picture of horror in which execution squads were said to have rounded up Mohammed's opponents, packed them into jail cells and then machine-gunned them to death as his forces began to lose in the fighting.

In a jail in Jaar, 10 miles north of here, 95 opponents of Mohammed were killed about 2 a.m on Jan. 18, including 50 who were gunned down in one cell when Mohammed's troops forced them to cluster in the center of the room and then fired at them through the windows, according to two of the captives, who said they survived because they lay underneath the bodies.

Villagers said they watched as a mass grave was dug and the bodies were buried hurriedly as Army forces opposed to Mohammed approached the province from Aden.

One survivor, Saleh Said, a civil servant, said Mohammed's gunmen returned to the cell at 6 a.m. Finding three captives mortally wounded but still alive, they dragged them outside and killed them, slitting the throat of one before a crowd of villagers, he said.

Six prisoners escaped by breaking through a window before the gunmen fired into the cell, according to Lt. Abdullah Abdul Jaber, one of the six. The cell shows evidence of shooting, with large bloodstains on the floor, freshly patched bullet holes in the walls and scarred window bars. Authorities said the walls were patched by Mohammed's forces to cover up the massacre.

Just outside the jail walls was what appeared to be a freshly dug mass grave in a small vegetable garden surrounded by a barrier of upturned automobiles.

Hussein Mohammed Mafari, 12, said he watched from a window of his nearby house as a bulldozer dug a trench and Mohammed's gunmen dumped in the bodies.

Lt. Col. Abdel Wahad, an Army brigade commander who led an advance on Abyan province on Jan. 20 against what he said was almost no resistance, said many victims were soldiers serving in a camp near here that had been commanded by a Mohammed supporter.

Wahad, talking to reporters in the office of former provincial governor Mohammed Ali Ahmed, a Mohammed supporter who was said to have fled, said the commander ordered troops loyal to the new regime to change to work clothes and report to their jobs in a productivity program in which soldiers are employed in civilian projects.

Wahad said those anti-Mohammed troops had then been taken to state security prisons, local jails and some schools and detained for four days without food or water. He said that in the village of Sheik Salim, about four miles from here, 15 unit commanders of the Army base were murdered.

Accompanying the wave of political murders, officials of the new regime said, was a campaign of plundering that will cripple the local economy for months to come.

Qarhi said the "clique of Ali Nasser gangsters" looted public corporations, taking their vehicles to transport ammunition and food and then keeping them. "The real goal of this clique was to eliminate our revolutionary experiment and the progressive regime of this country," Qarhi charged.

Abas Mansour, head of the party committee in Khanfar district, said Mohammed and three Politburo supporters were in a government guest house at Jaar, directing the offensive by radio and preparing to return to the capital once their opponents had been eliminated.

There were signs of damage to the guest house, which was bombed by the Air Force on Jan. 18 in an effort to knock out a broadcast studio Mohammed had been using.