An opposition human rights group accused police today of brutality during South Africa's six-day-old state of emergency, while the government announced the arrests of 118 more persons under its broad emergency regulations.

Also today, the South African Council of Churches called for the immediate release of the detainees and warned that South Africa faces "a disastrous aftermath" if it continues the large-scale crackdown on government opponents.

The official total of arrests following the declaration of the state of emergency, which took effect at midnight Saturday, now stands at 910. But a spokesman for the Detainees' Parents Support Committee said the organization believes dozens more persons have been detained, based on accounts received at their Johannesburg office.

Meanwhile, President Pieter W. Botha, in response to a call for negotiations over ending the state of emergency by Bishop Desmond Tutu, a black leader, said, "I am always willing to negotiate with anyone who does not propagate violence."

The spokesman for the parents' committee, who requested anonymity, said the committee had compiled several accounts of police misconduct from witnesses since the proclamation took effect.

Police spokesmen denied the accusation that police generally have used emergency powers as a license to terrorize township residents.

"We're trying to normalize the situation, and that means police must be seen by people in the community to have the utmost patience," said Maj. Steve van Rooyen. "We realize we can't restore peace by shooting people."

Among the most serious cases cited by the Parents Committee:

Two black youths alleged that they and a third person had been beaten in the Springs police station east of Johannesburg. According to the youths, they and a man named Joseph Hlwaele were arrested Sunday and taken to the station, where they were forced to strip naked and lie on a rug while police kicked and trampled them with their boots.

Family members reported two incidents in which police allegedly took hostages in Tambisa.

In the first, police came early in the morning to the home of Gregory Thulare, a student activist. When they found he was not there, they arrested his father Difa, a trade union shop steward, allegedly telling his family that they would release him when the son appeared. Gregory Thulare was detained later that morning, but the father was not released, the spokesman said.

In the second incident, police came to a house to arrest another student activist. When they could not find him, they took into custody his sister's 4-year-old son, saying they would trade the child for the activist. They released the child the next day, according to family members, although they had not found the student.

The spokesman said the committee also has eyewitness accounts of random beatings with gun butts and whips called sjamboks by police in the townships of Tsekane and Alexandra Monday and Tuesday.

Police spokesman van Rooyen confirmed that Difa and Gregory Thulare both had been detained under the emergency powers act, but said he could not comment on the specific allegations of police misconduct.

Under the emergency regulations, the police force and the Army have the power to arrest anyone deemed a threat to public safety in 36 districts, including the cities of Johannesburg and Port Elizabeth.

The Council of Churches' statement today warned that by detaining clergymen, labor leaders and community workers, the government was taking from black townships "the restraining hand of mature leadership."

Few incidents of unrest were reported today.

Meanwhile, another 447 persons were arrested yesterday by police in the Transkei, a nominally independent black "homeland" in eastern Cape Province, the homeland commissioner of police reported this morning. He said that most were later released but that 170 had been held and charged with various offenses.