Nato troops in Bosnia-Herzegovina have carried out early morning raids on the homes of the children of the indicted war criminal, Radovan Karadzic.
Nato forces arrived in the middle of the night
A Nato spokesman said they believed Sasa and Sonja Karadzic to be part of a network supporting their father.
Radovan Karadzic, the Bosnian Serb leader during the Yugoslav civil wars, has been on the run for 11 years.
He and his military chief, Ratko Mladic, are wanted on genocide charges by the UN tribunal in The Hague.
The spokesman said that troops had to force their way into Sonja Karadzic's house because no-one had answered the door.
Neither Sonja nor Sasa Karadzic were arrested, but they were questioned for several hours before the soldiers left.
The soldiers also searched the homes and took away several items for "examination".
"We're doing that due to a belief that they are intimately involved in the support network that allows Radovan Karadzic to remain at large," said spokesman Derek Chappell.
"We have been here before, and we'll come back again and again as the evidence suggests they are involved in this network."
The operation was carried out in Pale, a town 15 kilometres (nine miles) east of the capital Sarajevo, at 0300 local (0200GMT).
Sonja Karadzic refused to talk to reporters after the raid.
The operation lasted several hours
"I have spent six hours in front of a camera...if you want my statement, ask them to give you the material". However, during the raid she spoke to AP news agency when they called her.
"Someone is breaking in. We and the neighbours asked who they are and they said 'police'," she told AP before hanging up.
Mr Chappell said the soldiers had to use "minor force", according to the AFP news agency, but he maintained there was no resistance once they entered.
Nato forces also took away six boxes of material for forensic examination, the agency said.
Television footage of Sonja Karadzic's home after the raid showed the front door had been forced and possessions inside were in total disarray.
The UN tribunal has indicted Mr Karadzic for genocide over the siege of Sarajevo and the massacre of thousands of Muslims in Srebrenica during the 1992-95 Bosnian war.
He has been at large for 12 years, despite a number of high-profile operations to capture him. Most however have ended in embarrassing failure.
In April 2004, special forces carried out a raid on church buildings in Pale where they believed Mr Karadzic was visiting. He was not there - but a priest and his son were seriously injured in the attempt to find out.
Recently Rafi Gregorian, deputy to the EU's special envoy to Bosnia-Herzegovina, said Radovan Karadzic was in contact with his family and supported them financially.
The US government has offered a reward of US$5m for information leading to the arrest of Mr Karadzic or his army chief General Ratko Mladic.