BEIRUT, Lebanon (AP) _A powerful car bomb exploded Wednesday in Syrian-policed west Beirut, killing four people and wounding 19.

The blast came shortly before the expected arrival of newly elected President Rene Mouawad in the city’s Moslem sector.

The booby-trapped car went off in the Caracas neighborhood, about three blocks from the posh villa where Mouawad planned to stay.

The presidential palace, traditional seat of the head of state, is occupied by rebellious army commander Gen. Michel Aoun, who rejected Mouawad’s election Sunday by members of Parliament under a peace plan Aoun opposes.

The peace plan shifts political power to the Moslem majority, and Aoun has specifically criticized it for not including a timetable for a withdrawal of Syria’s estimated 40,000 troops.

Police said four people were killed and 19 wounded in the blast Wednesday. Window glass of apartment and office buildings was shattered by the 3:15 p.m. explosion.

Half a dozen cars were set ablaze in a parking lot as Syrian soldiers, clutching AK-47 rifles, converged on the scene. They fired in the air to make way for ambulances and fire engines that raced to area, the witnesses said, insisting on anonymity.

Also Wednesday, the Lebanese Communist Party chief was quoted as saying his militia may try to kill Aoun for rejecting the election of Mouawad, a 64-year-old Maronite Catholic.

Sources said that before the end of the week, Mouawad would announce formation of a national reconciliation government to end 14 years of civil war.