BOSNIA . . . SERBS OPEN SARAJEVO TO INTERNATIONAL AID

Serbs allowed two trucks carrying construction materials and firewood to enter Sarajevo today. U.N. officials said that the cooperation, however limited, with international efforts to aid the devastated city signals that a month-old truce in Bosnia is holding. The concession by the Serbs accompanies a general lessening of armed conflicts in the area following the New Year's Eve ceasefire declaration. "We'll see more humanitarian aid entering the city," promised Enrique Aguilar, the chief U.N. civil affairs officer.