"We have detained an individual ... for suspected activities contrary to the Dayton agreement" that ended Bosnia's 1992-95 war, Stabilization Force (SFOR) spokesman Mark Hope said.

Hope refused to disclose further details, but the detainee was identified in the local media as retired Bosnian Serb army captain Rajko Banduka, who served during the war under Mladic.

Banduka had been arrested in his apartment in the northeastern town of Bijeljina, SRNA news agency reported.

Hope said the detainee was in a "secured detention facility where investigations will continue."

"We are currently conducting a search of his residence in Bijeljina," he added.

Mladic has been indicted by the UN war crimes tribunal at The Hague for war crimes and genocide, particularly to the 1992-95 siege of Sarajevo, in which some 12,000 civilians died, and the 1995 massacre of more than 7,000 Muslim men and boys in the eastern Bosnian town of Srebrenica.

UN prosecuters claim he is hiding in neighbouring Serbia but the authorities in Belgrade deny any knowledge` of his whereabouts.

WAR.WIRE