A bomb exploded today in the Bosnian Serb town of Banja Luka (BAHN-yuh LOO-kuh), the headquarters of President Biljana Plavsic (bill-YAH-nuh PLAHV-sitch). One person was killed. And, at the site of yesterday's violence in Brcko (BIRCH-koh), United Nations team was driven out of town by a rock-throwing crowd. They had gone into Brcko to see if it was safe for its unarmed policemen to return. NPR's Edward Lifson reports.