A car bomb exploded near a Syrian army checkpoint in south Beirut Tuesday, touching off a gun battle between Syrian troops and pro-Iranian fundamentalist militiamen, police said.

They said at least five people were killed and 30 wounded in the mid-afternoon blast in south Beirut's seaside Ouzai district. It was the third car bombing in Lebanon this year.Among the wounded were two Syrian soldiers and two Lebanese policemen who were manning a joint checkpoint on the Ouzai highway, police said.

The site of the blast was about 300 feet from an office of the Iranian-backed Hezbollah, or Party of God, the most radical Shiite Moslem group in Lebanon.

A carload of bearded Hezbollah gunmen raced to the blast scene. Syrian soldiers and Lebanese policemen stopped the car and beat the gunmen with rifle butts through the windows, according to reporters who watched from a distance.

The gunmen resisted and one drew a pistol and fired. Troops and policemen then opened up with submachine guns over the car's roof. Panicky onlookers sprinted away, and there was no immediate word on casualties.

Syria deployed an estimated 2,400 troops in Beirut's southern slums two weeks ago to quell three weeks of savage fighting between Hezbollah and the pro-Syrian Shiite Amal militia.

Police had said 296 people were killed and 1,000 wounded in the war for control of slums, where most of the 18 foreigers kidnapped in Lebanon are believed held.

After the bomb-laden brown Datsun blew up at 4:05 p.m., ambulances were seen racing to and from the blast scene and fire engines doused at least two burning cars with water hoses.

Syrian troops and policemen quickly removed debris from the area, where five shops were damaged.

Today's car bombing came eight days after a car bomb detonated in Christian east Beirut's Rmaeil residential neighborhood, killing 20 people and wounding 78.

On April 23, a car bomb blew up in a crowded vegetable market in the predominantly Sunni Moslem port city of Tripoli, killing 69 people and wounding 111.

There has been no claim of responsibility for any of this year's bombings. But leaders in Tripoli blamed the Lebanese Forces, the Christians' main militia, for the blast there.

The Lebanese Forces command, which denied involvement in the bombing, accused the Syrian secret service of masterminding the Rmaeil car bombing.