GRACKO, Yugoslavia (AP) _ Soldiers crouched combat-ready in fields and a NATO helicopter thundered overhead as relatives buried 14 Serb farmers Wednesday near the site where they were gunned down last week.

The heavy NATO security for the funeral in this farming village sought to rebuild the damage done by the slayings, which deeply undermined Serbs' already shaky confidence in peacekeepers' pledges to protect all ethnic groups in Kosovo.

NATO officials also detained four men for questioning about the killings, but offered no word on their ethnicity or other details. Serbs accuse ethnic Albanians in the killings.

New deaths were also reported in ethnic violence that has plagued the six-week-old peacekeeping mission. The Beta news agency said four Serbs were killed Tuesday and three were missing in southeast Kosovo. NATO confirmed finding Serbs and Albanians dead in northern Kosovo the same day.

``They are criminals,'' one woman at the funeral moaned as she stroked the wooden coffins of her four relatives, all members of the Janicijevic family. The farmers were shot while harvesting wheat in a field outside Gracko on Friday.

Along with the wails of mourners came the chatter of a NATO helicopter overhead. Armored vehicles lined the main road into and through Gracko, a village 10 miles south of Pristina, Kosovo's capital.

British soldiers toting automatic rifles were posted around the funeral and in the general area _ some crouching, combat-ready, in fields around the village.

Serb officials complain that NATO has not done enough to stop attacks by ethnic Albanians seeking revenge for the campaign of massacres and expulsions waged against them by Serb-led Yugoslav troops in March. About 10,000 ethnic Albanians were killed in that campaign and more than 800,000 were driven out or fled Kosovo.

Tens of thousands of Serbs have fled the province, fearing revenge attacks, since Serb forces left Kosovo in June and peacekeepers came in after the 78-day NATO bombardment of Yugoslavia ended.

In Belgrade, the Yugoslav government accused peacekeepers of allowing a ``security vacuum'' in Kosovo, allowing the ``ethnic cleansing'' of the province's non-Albanian minority.

In Gracko, the 14 wooden coffins were lined up on an asphalt-covered playground, and friends and relatives lay flowers, wreaths and written prayers on the caskets.

Patriarch Pavle, head of the Serbian Orthodox Church, sought to console relatives. ``Suddenly they depart this world, but their only consolation is they didn't depart this world like criminals, like the ones who took their fields and are burning our houses,'' he said.

Another speaker, local resident Stefan Lalic, urged Serbs not to abandon their village. ``We must stay so that our church doesn't become Muslim,'' he said, referring to the predominant religion among Kosovo's majority ethnic Albanians.

``We have to stay here because of our dead and missing. The war of graves is not over yet,'' he said.

Joining the 350 mourners was Bernard Kouchner, the new U.N. administrator in Kosovo, who has pledged to carry out the peace mission despite what he calls the cycle of ethnic violence.

``We must find the truth,'' he said, pledging that justice would prevail in the Gracko case.

Maj. Jan Joosten of Denmark, a spokesman for the peacekeeping mission, said four men had been detained at dawn after British military police searched houses in Gracko and around the nearby town of Lipljan. He said the four would be questioned, but had not been charged.

Joosten also confirmed Yugoslav media reports that the bodies of two Kosovo Serbs were found Tuesday, apparently slain in an ambush on their car in the northern Kosovo town of Vucitrn. The same day, peacekeepers found the bodies of three ethnic Albanians and one Bosnian Muslim in the town of Pec.