BELGRADE, Yugoslavia (AP) _ Serbian police briefly detained the Bosnian Serb president at the Belgrade airport, independent media reported today.

Biljana Plavsic, president of the 49 percent of Bosnia controlled by the Serbs, tried to fire her police chief over the weekend, angering supporters of former Bosnian Serb leader Radovan Karadzic.

Plavsic was detained in Belgrade on Sunday evening when she flew in from London, B-92 radio reported. She was kept for more than an hour and then escorted to the Bosnian-Serb border.

Plavsic's brother, Zdravko, confirmed the incident on the radio station. He said he spoke to his sister by telephone and that she said she had been treated well by police.

The independent Beta news agency reported that Plavsic was handed over to Bosnian Serb police and was held in the Bosnian town of Bijeljina all evening Sunday.

However, Plavsic's spokeswoman, Milka Tosic, would not say if Plavsic had been detained in Bijeljina.

Plavsic tried Saturday to fire Interior Minister Dragan Kijac, who is loyal to Karadzic. The Bosnian Serb government defied Plavsic, accusing her of betraying Serb interests.

Karadzic, although officially stripped of power after being charged with war crimes by a U.N. tribunal, still wields enormous influence and controls the Bosnian Serb police.