U.N. military observers, hoping to head off potential fighting for a strategic corridor, moved into place near BRCKO. Bosnian Serbs blocked a GORADZE-bound medical convoy for the fourth straight day.

There was no further word on the movement of Bosnian Serb tanks through the protected zone around SARAJEVO, but the United Nations reported cease-fire violations.

Talks continued in VIENNA, Austria, between Bosnian Croat and Muslim-led government leaders on details of a U.S.-brokered federation. The two sides reported progress Saturday on filling key leadership posts and defining boundaries of cantons.