BEIRUT — Syria’s civil war spilled over into neighboring Lebanon once again on Sunday, with gun battles in the northern city of Tripoli between supporters and opponents of President Bashar Assad’s regime that left four dead.

The fighting between pro- and anti-Assad gunmen flared as bodies of three Lebanese — who were killed after crossing into Syria to fight in the civil war — were brought back home for burial. In addition to the four killed, 12 people were wounded in the gunfights.