NATO TO ESCORT RIGHTS GROUPS\Role will not conflict with main mission in Bosnia, Perry says.

Byline: Eric Schmitt The New York Times

Signaling that NATO soon will broaden its duties in Bosnia and clarifying U.S. policy on a sensitive topic, Defense Secretary William Perry says that, beginning later this month, U.S. and other alliance troops will provide security for human rights investigators looking into evidence of massacres and war crimes in Bosnia.

Under the terms of the Balkan peace plan reached in Dayton, Ohio, in November, the main military missions of the 60,000-member force are to supervise the marking of cease-fire lines and ensure that the rival forces withdraw from those boundaries.

But in an interview, Perry said that once NATO forces are deployed in large enough numbers to protect themselves, the troops would also guarantee freedom of movement and security to all civilians and international organizations traveling through Bosnia, and are likely to provide escorts for human rights investigators.

"If the War Crimes tribunal wants to go to Srebrenica and dig up some graves, we'll provide the security that allows them to do that," Perry said, referring to the suspected massacre of Bosnian Muslims in the eastern Bosnian enclave. "I don't consider that mission creep."

The defense secretary's comments came in the aftermath of reports that Bosnian Serbs were using a vast open-pit mine in northern Bosnia as a mass grave for thousands of Muslim and Croat victims of "ethnic-cleansing."

With his remarks, Perry clarified U.S. intentions on a subject of intense concern to human rights groups and the international tribunal in The Hague that is investigating war crimes.

Graham Blewitt, a deputy prosecutor with the tribunal, told Reuters on Friday that if the NATO-led troops would secure suspected mass graves they could be exhumed in spring for use as evidence.

Perry's comments mark a sharp departure from the way Americans and other allied troops have operated so far.

British and U.S. soldiers and officers interviewed near reputed killing fields in recent days have declared it was not their business to monitor or police sites of potential war-crimes evidence.

Some have worried that raising the issue would endanger NATO's carefully nurtured relations with the Bosnian Serbs, who already suspect the West of being partial to the Muslim-led Bosnian government.

It was the revelation of the massacre of up to 6,000 Muslims there that helped shock the United States into a more aggressive peacemaking role.

Reporters exploring this and other suspected grave sites this week have been arrested by Bosnian Serbs.

An official at the Tuzla headquarters of the U.S. forces in Bosnia said the NATO force has its hands full. "Expansion of the mission is not something we're looking to do."

The peace accord gives ground commanders the authority to help with other tasks, like delivering relief supplies and safeguarding the repatriation of refugees, if these duties do not interfere with their main mandate.

But administration officials have not focused on that part of the agreement in an effort to avoid angering lawmakers who oppose United States participation in the Bosnia operation.

Perry's remarks, made Thursday, foreshadow new political guidance to ground commanders in Bosnia who have resisted taking on any new missions until they complete their primary goals.