Eighty-nine villagers have been arrested, and residents say armed police have been laying siege for six days to hundreds of others who fled into surrounding bush country after the killing of two policemen in this black reserve north of Pretoria.

Persons interviewed near the village of Keerom today said the fugitives, desperate for food, were living on edible roots and wild berries in the bush and were drinking rainwater from muddy pools.

Meanwhile, others interviewed here said they were among 257 residents of the reserve who were locked in a hall on New Year's Day and tortured by members of a tribal militia. They further charged that the chief minister and a Cabinet member of a black "homeland," to which the Pretoria government is about to grant nominal independence, watched and at times participated in the torture -- described as an attempt to crush their resistance to incorporation into the homeland.

Police have confirmed only the arrest of the 89 villagers. "All I can say with the facts available to me at this stage is that it does not sound as though the allegation of a siege can be true," said Col. Jaap Venter.

The atmosphere has been tense since Pretoria's decision to force the annexation of Moutse, with its 120,000 inhabitants, into the neighboring KwaNdebele homeland.

KwaNdebele is due to be granted independence some time this year under the terms of South Africa's apartheid policy of racial partition. Most persons of Moutse, when asked, have said that they oppose being part of the tribal state and thereby losing their South African citizenship.

Violence linked to the forced incorporation has led to 21 deaths, including the two policemen, and many Moutse residents are saying they will fight rather than accept the annexation, which became law last Wednesday.

Pretoria has insisted on the annexation going ahead, in apparent contradiction of its declared intention to phase out apartheid -- which is based on the concept of independent homelands -- and to end forced population removals.

The government has offered no reason for insisting on the annexation in the face of expressed opposition. It has said objectors can be moved at government expense to a resettlement camp at a place called Emmerpan, about 50 miles away. Nobody interviewed here in recent days has been willing to move.

The chief minister of KwaNdebele, Simon Skosana, said in a statement tonight that the impression given that Moutse residents were being forced to subject themselves to his administration was untrue and can be ascribed "to revolutionary elements who represent only a small minority in Moutse."

He said this minority had organized illegal meetings, where decisions had been made to attack government property and shops belonging to people well disposed toward the homeland administration, allegedly 80 percent of the populace.

The chief minister did not say how he arrived at this assessment. No referendum has been held, and tribal chiefs and other community leaders in Moutse claim opposition to incorporation is almost total. Skosana did not comment on the allegations of torture, which he is accused of having witnessed.

Independent verification of events here has proved difficult. A broadcast yesterday warned that reporters entering this latest site of South Africa's racial unrest would be arrested.

Informants interviewed today within a few miles of Keerom said they had smuggled food to the besieged villagers in the bush. They would not give their names because they said they feared reprisals by the authorities.

According to their account, two black policemen arrived at Keerom village on New Year's Day, when the annexation of Moutse went into effect, and interrupted a community meeting to discuss resistance to the incorporation.

A clash ensued, during which the policemen fired several shots, wounding three persons, one of whom later died. As the crowd's anger flared, the policemen fled, according to those interviewed, but they ran into another crowd holding a similar meeting.

There a section of the crowd set upon the two policemen and killed them. Next day, those interviewed said, a large contingent of police arrived. The terrified villagers abandoned their homes and fled into the surrounding bush country. According to these sources, the police have remained in occupation of the villages ever since, waiting for the fugitives to return.

Yesterday, according to persons interviewed, the police mounted a major search of the bush country, using a helicopter. Police later confirmed that there had been 89 arrests relating to the death of the policemen.

Field workers of the Black Sash civil rights organization have taken statements from 37 of the 257 Moutse residents who say they were tortured by members of a KwaNdebele militia.

The 37 residents charged that they were rounded up by armed men who burst into their homes early Jan. 1, put their families to flight, looted their houses and dragged the men to trucks.

In the KwaNdebele capital of Siyabuswa, they said, they were forced to enter a large community hall by walking between two 20-yard columns of men who flogged them with horsewhips.

"Inside the hall I found Mr. Skosana," said one informant, whose detailed statement was corroborated by nearly all the others. He added that another member of the homeland Cabinet, Interior Minister Piet Ntuli, was in the hall and taunted the prisoners, "calling us dogs and many other more vulgar things."

The statements allege further beatings and degrading treatment by the militiamen, ending only with the arrival of police.