President Corazon Aquino named a human rights committee today and gave it broad powers to investigate widespread killings, torture and unexplained disappearances attributed to the Philippine military during the rule of deposed president Ferdinand Marcos.

Aquino's readiness to probe the military's human rights record, her recent release of top Communist leaders from jail, and her inability to bring a quick cease-fire in the conflict with Communist insurgents while she tries to negotiate with them are combining to maintain tensions between civilian and military leaders in her government, western and Filipino observers said. Several top military officers, including Defense Minister Juan Ponce Enrile, also served under Marcos.

The appointment of a human rights committee came amid further reported fighting between government forces and the Communist New People's Army, bringing the death toll to more than 100 in the three weeks since Aquino took power.

While virtually all Filipinos say they want a thorough investigation of rights violations under Marcos, many say they are also worried about conflicts that might result.

Newspaper columns and casual conversations raise the prospect that a full revelation could divide the civilian and military leaders who jointly overthrew Marcos last month.

"When we speak really of human rights violations in the context of the Marcos regime, military involvement is very much a central part of it," said Aquino's spokesman, Rene Saguisag, in announcing the new investigation.

Human rights organizations in the Philippines have said Marcos' government summarily executed 2,256 people from 1977 to 1986. Other groups, such as the London-based Amnesty International, say Marcos' military authorities regularly tortured prisoners and gunned down civilians suspected of sympathizing with the Communists.

The seven-member Presidential Committee on Human Rights includes several members of human rights groups whose leaders remain privately critical of Aquino's military officeholders, charging them with having willfully failed to prevent or investigate human rights abuses by the military during Marcos' years. The committee chairman, former senator Jose W. Diokno, and committee member William Claver are leaders of one such organization, the Free Legal Assistance Group.

A third member, the Rev. Marianni Dimaraanan, is director of a human rights group known as Task Force for Detainees. Both organizations have privately criticized armed forces chief of staff Gen. Fidel Ramos and Defense Minister Enrile, although not in public statements, since Aquino appointed them to her new government last month. Ramos and Enrile led the military rebellion that helped oust Marcos.

Aquino's civilian supporters share the human rights activists' suspicions of Enrile. Political prisoners released by Aquino have predicted that Enrile would be tarnished by any thorough investigation of past military practices.

"We would be faced with a real crisis if he were found guilty," one official said recently. Reflecting on support for Enrile within the military officer corps, he said, "It would be difficult to keep him, but certainly difficult to make him go."

Enrile and other top military figures have warned against Aquino's policy of reconciliation with the Communist rebels, including her orders to release all political prisoners and her plans for a six-month truce. Enrile repeated the warning yesterday, saying the government should press the Communists to show quickly that they plan to join the truce.

Enrile suggested that the government's efforts to draw guerrillas, whose armed regulars are estimated to be about 12,500, down from the hills had been ineffective. He accused hard-line Communist units of stepping up their attacks on government forces. The military "have been suffering casualties because they want to heed the call of our president for unity and reconciliation," Enrile said.

Reports by the government and newspapers have recorded more than 100 dead in attacks by suspected Communist rebels since Aquino took power on Feb. 25. Three clashes reported today, including an attack on a police station on the battle-torn island of Mindanao, were said to have killed at least 27 persons.

Gen. Ramos parachuted into a field of sugar cane today on the central island of Negros, where the insurgency has grown the most rapidly in recent years, and called on residents to cooperate with the military in seeking peace.

It remained unclear whether Aquino's human rights committee would press to reopen the investigation into the 1983 killing of her husband, Benigno (Ninoy) Aquino Jr., then Marcos' most prominent political opponent. Aquino has avoided calling for a retrial of the 25 military officers and one civilian acquitted last December. The trial was widely regarded as a sham.

But since Marcos' fall last month, the chief prosecutor in the trial has announced that Marcos had intervened personally to ensure the acquittal of the men, including his military chief, Gen. Fabian Ver.

Public pressure for a retrial has grown in recent weeks, and many of the defendants are being held in custody. Manila's Philippine Daily Inquirer showed a sketch of Aquino's bleeding body today on its front page, beneath the headline "People Power Push Justice for Ninoy."

In another development, Political Affairs Minister Antonio Cuenco said today that four out of the five Cabinet members assigned to study the issue of a revolutionary government will recommend Wednesday that, instead of a unilateral declaration, the National Assembly be convened in two months to give Aquino emergency powers.