Nato forces in Bosnia burst into the homes of the children of Radovan Karadzic this morning, in the latest attempt to track down the suspected war criminal who has been on the run for 11 years.

Squads of heavily armed and masked troops raided the properties of Karadzic's son, Sasa, and daughter, Sonja, in the Bosnian Seb stronghold of Pale, near the capital Sarajevo, at 3am local time (2am GMT).

The troops removed six boxes of material which Nato says will undergo forensic examination, and then subjected Karadzic's children to hours of questioning.

Nato is thought to suspect that Karadzic's children are helping him evade justice by failing to disclose details of his whereabouts.

In a statement, it said its operation was conducted in cooperation with the International Criminal Tribunal for the former Yugoslavia (ICTY) in an effort to expose Karadzic’s support network and determine his location.

Squads of heavily armed and masked Nato troops and many military jeeps were present outside the entrance to the building, according to journalists at the scene.

David Chappell, a Nato spokesman, said the operation had been a success.

“We are pleased with the operation. The people who have been interviewing Sonja and Sasa said that the interviews were very useful," he was quoted as saying by the Agence France Presse (AFP) news agency.

Karadzic's daughter, Sonja Karadzic-Jovicevic, refused to answer questions from reporters, only saying that her family were awoken when troops burst through her door.

“I spent six hours in front of a camera. If you want my statement, ask them to give you the material,” she was quoted as saying.

Karadzic and his former military chief, Ratko Mladic, have been on the run from The Hague-based UN war crimes tribunal for more than 11 years since being charged with crimes committed during Bosnia’s 1992-1995 war.

The genocide charge is related to the July 1995 massacre of around 8,000 Muslim males in the wartime eastern enclave of Srebrenica, the single worst atrocity in Europe since World War II.

Authorities have little knowledge of Karadzic’s whereabouts, but he is thought to be hiding in the Serb-controlled part of Bosnia or in a remote part of neighbouring Montenegro, where he spent his childhood.

Many nationalist Serbs still regard Karadzic and Mladic as heros, and it is thought his supporters could be protecting him.

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