Nato-led peacekeeping troops have raided the family home of Bosnian Serb war crimes suspect Radovan Karadzic.

They described it as an operation to disrupt illegal smuggling.

A guard at the house in Pale, within the Bosnian Serb Republic, said masked French troops from the Stabilisation Force (S-For) swooped in by helicopter before dawn and told him they were looking for weapons.

My guess would be it's an effort to show that... S-For remains on the job

Mark Wheeler, International Crisis Group

A spokesman said they took away a small number of firearms and forged documents from the house, which is reported to have been empty for five years.

The troops forced open the gate of the 15-room house, blew one door open, shot through a glass door and ripped up parquet flooring.

"They broke in, threw me on the ground and tied me up," said the guard, 66-year-old Rade Glavonjic.

Mr Karadzic's wife, Ljilana Zelen-Karadzic arrived at the house an hour after the raid to inspect the damage. Later Bosnian Serb police investigators moved in.

The raid came as S-For's future was thrown into doubt by the US veto of a United Nations peacekeeping mandate for Bosnia.

"My guess would be it's an effort to show that... S-For remains on the job," said Mark Wheeler, Bosnia representative of the International Crisis Group, a non-governmental organisation specialising in conflict resolution.

"This looks like a PR exercise, but an understandable one."

Nato spokesman Mark Laity denied this: "We are in Bosnia to do a job and part of that job is what we did today - it's nothing to do with a public relations exercise."

Attempted seizures

Nato troops have been searching for the former Bosnian Serb president - the UN war crimes tribunal's most wanted suspect - since Nato airpower ended the 1992-95 Bosnian war.

He has been indicted at the international war crimes tribunal in The Hague on charges of genocide.

S-For tried in vain to seize him in February and March, raiding locations in eastern Bosnia.

Mrs Zelen-Karadzic said she had met S-For officers on a number of occasions, and they could have asked for the keys to the house.

"It's quite clear that Radovan cannot hide under the carpet or behind the paintings," she said.

S-For said in a statement: "This operation highlights S-For's active role to disrupt particularly dangerous criminal activities and smuggling rings."