A U.S. relief plane was hit by Serb gunfire Saturday, and all aid flights to Sarajevo were canceled.

The gunfire underscored the mounting tensions between U.N. peacekeepers and Bosnia’s warring sides, which have resumed fighting in recent weeks despite a cease-fire that ostensibly remains in effect.

The 10 bullets that hit the C-130 transport plane during takeoff came from rebel Serb positions northwest of the airport, U.N. spokesman Maj. Herve Gourmelon said.

There were no injuries and the plane flew on to Anocona, Italy.