Beirut ? Shouting “Death to Israel” and waving yellow Hezbollah flags, thousands of people marched Monday behind the coffin of a guerrilla killed in the heaviest combat in six years along Lebanon’s border with Israel.

A U.N.-brokered truce held a day after Sunday’s fighting, but tensions remained high. Ten Israeli warplanes flew over Lebanon’s south, east and north, the Lebanese army said.

U.N. Secretary-General Kofi Annan expressed concern at the weekend fighting and called on all parties to exercise maximum restraint and respect the border drawn by the United Nations after the withdrawal of Israeli troops from southern Lebanon in 2000.

Sunday’s fighting erupted when Hezbollah guerrillas fired rockets into northern Israel. The Israeli military retaliated with airstrikes on guerrilla positions, and both sides then traded artillery and rocket fire.

Two militants died and six were wounded in the clashes, while two Israeli soldiers were wounded. An Israeli general claimed Monday that his forces destroyed most of Hezbollah’s military positions in southern Lebanon.