Nearly a third of Kosovo refugee families suffered human rights violations such as killings, beatings, torture, sexual assaults and looting before being forcibly expelled to neighboring states as part of a "systematic and brutal campaign" by Yugoslav forces, according to a survey released yesterday.

The population-based survey, the first of its kind among ethnic Albanian refugees, was conducted to measure the pervasiveness of the violence and human rights abuses in Kosovo that have been consistently reported since a NATO bombing campaign began March 24 and thousands of ethnic Albanian civilians started spilling into neighboring Albania and Macedonia.

"The level of violence inflicted on people who were interviewed was higher than we expected," said Leonard S. Rubenstein, executive director of Physicians for Human Rights, which carried out the survey with three other groups.

The groups interviewed a random sample of 1,180 Kosovo refugees in 31 camps in Albania and Macedonia in April and early May. The respondents represented households totaling 11,458 members in 23 of Kosovo's 29 municipalities.

A 148-page report on the survey, entitled "War Crimes in Kosovo: A Population-Based Assessment," also documented destruction of 100 medical clinics, pharmacies and hospitals in Kosovo and the targeting of ethnic Albanian doctors. It recommended adding another charge to the war crimes indictment of Yugoslav President Slobodan Milosevic: "violating medical neutrality." Half of those interviewed, it said, reported witnessing such violations, including destruction of medical facilities and forced evacuation of medical workers and patients.

Attacks on the medical system in Kosovo "began long before the bombing," Rubinstein said. "There was a systematic attack on facilities that are supposed to provide relief from suffering. We can only conclude that Serb forces were trying to increase suffering and that it was another means of attacking the Kosovo Albanian civilian population."

In its report, Physicians for Human Rights also called on the United States and its NATO allies to makes sure of the departure of Yugoslav forces, including Army, Interior Ministry and paramilitary personnel, before attempting to return refugees to their homes. "Clearly, the participation of Serb forces throughout Kosovo in abuse of one form or another . . . should preclude their presence within Kosovo in any numbers in the future," the group said.

According to the survey, 35 percent of the respondents either witnessed killings by Serb police or soldiers or saw the bodies of victims. Nearly a third reported beatings by Serb forces, and almost half said they were robbed.

Of the interviewees, 91 percent said they were "forced, directly or indirectly, to leave their homes simply on the grounds that they were Kosovar Albanians." Only five of the 1,180 said the Kosovo Liberation Army caused their flight.

"Contrary to Serb media reports," the report adds, "not one survey participant cited NATO bombings as a reason for displacement from their home."