It was another stiflingly hot night July 14, so Medine Oncel and her younger sister, Devran, like many in this mainly Kurdish city, decided to sleep on the balcony of their seventh-floor apartment.

"It was around 3 a.m. when we first heard the voices," Devran, 15, recalled in an interview. "When we looked down, we saw four armed policemen. Two of them had black ski masks over their heads." Within minutes, she said, they had broken into the building and into the Oncel home.

"They said they wanted to take me and Medine in for questioning," Devran said. "I headed for the bedroom to get dressed, but Medine . . . went straight to the window and jumped."

Duriye Oncel, the girls' mother, explained: "My daughter, you see, preferred death to being tortured once again."

Medine's story is not unique in Turkey, as Harold Hongju Koh, the U.S. assistant secretary of state for democracy, human rights and labor, discovered today in Diyarbakir as he was briefed by human rights activists. Koh arrived in Turkey on Thursday to undertake what he described as a "listening tour" that will include stops in Istanbul, the southeastern province of Sanliurfa and the capital, Ankara.

Human rights groups frequently accuse the U.S. government of turning a blind eye to Turkey's human rights record. They say Washington puts a higher priority on good relations because of the country's strategic location south of the former Soviet Union and northwest of Iraq.

"The West, and the United States especially, continue to assess Turkey on the basis of its strategic importance as a NATO member and its commercial value as a huge arms and consumer goods market," charged Nazmi Gur, a leading Turkish human rights activist. "The issue of human rights only comes up when they want to extract further concessions" from Turkey.

Although Koh's visit is not the first by a State Department human rights official, rights advocates here hope it will signal to the country's new coalition government, led by Prime Minister Bulent Ecevit, that the Clinton administration may no longer be as accommodating.

Medine Oncel, a 22-year-old brick factory worker, had never quite recovered from her first detention last November by Turkey's anti-terror police, according to her sister and mother. She was rounded up, they said, along with about 100 members of the pro-Kurdish People's Democracy Party for staging a hunger strike in support of the Kurdish rebel chief, Abdullah Ocalan.

Ocalan, who was captured by Turkish special forces in Kenya in February, was condemned to death by a Turkish court in June for founding and leading the Kurdish Workers' Party's 15-year uprising for Kurdish independence. The Turkish parliament must approve the death sentence, which has been appealed by Ocalan's lawyers, before it can be carried out.

Family members and cellmates said Medine, a staunch Ocalan supporter and militant Kurdish nationalist, was severely beaten and sexually abused during the 10 days she spent in a detention center. "Medine always said she would kill herself rather than go through the same hell again," Devran said. "I never thought she'd have the guts to do it, but she did."

The government has classified Medine's death as a routine suicide. It has not commented on allegations that it was linked to her earlier imprisonment. But it has acknowledged police abuses in general and vowed to bring them under control.

Ecevit, a former poet and journalist, on June 25 issued a sternly written warning against police abuses. Within days, however, two men died in custody in the western provinces of Izmir and Cannakale. Both bore marks of torture.

"If the allegations are true, this is an absolute disgrace," said Mehmet Ali Irtemcelik, Turkey's newly appointed minister in charge of human rights. Formerly one of Turkey's top diplomats, Irtemcelik said, "there are serious problems that need to be solved, and not because the West tells us to do so but because we Turks want a better democracy for ourselves."

Western governments have applauded recent legislation abolishing the presence of a military officer in special security courts, which are handling Ocalan's case. Irtemcelik says his government is determined to push legislation through parliament that will crack down on abuses and drastically increase penalties for security officials accused of torture.

Too often, however, rights groups complain, such laws even when passed, are never enforced.

Recent figures show nearly 400 torture victims applied for treatment at rehabilitation centers operated by the Human Rights Foundation since the start of the year. Commonly applied torture methods include electric shocks, beatings of the soles of the feet and genitalia, and sexual violation with truncheons.

Some particularly severe abuses have allegedly occured here in the mainly Kurdish southeast provinces, where rebels of Ocalan's outlawed Kurdish Workers' Party are keeping up their armed campaign in defiance of their captured leader's call for a cease-fire. They have killed more than a dozen Turkish soldiers during the past month alone.

About 300 villagers displaced by the violence ululated and flashed the victory sign when Koh toured the Cemal Yilmaz slum area today with city officials of Diyarbakir, 400 miles southeast of Ankara. Mehmet Atli, a father of nine who was kicked out of his village six years ago by Turkish security forces, said he told his story to the American visitor, who made no comment to reporters.

"We asked him for help to go back to our village, to help end this war and our suffering," Atli said. "It's about time America took pity on us Kurds."