World IN BRIEF : BOSNIA-HERZEGOVINA : Fighting Escalates in Supply Corridor

Fierce artillery duels rocked a vital Serb supply corridor in northeastern Bosnia, threatening to draw the powerful Yugoslav army back into the conflict. The United Nations reported 1,000 shell explosions in three hours in the narrow corridor that links Bosnian Serb holdings in the northeast to Serb-controlled areas in Croatia and to Serbia proper in neighboring Yugoslavia. The shelling duel prompted a rare announcement by Bosnian Serb forces that they were closing the road for an indefinite period. Bosnian Serbs reportedly are trying to widen the corridor to prevent government and Bosnian Croat troops from closing off the supply route altogether.