BEIRUT, Lebanon - Former Prime Minister Rafik Hariri, a billionaire who helped rebuild his country after decades of war but had recently moved to the opposition after a dispute with Syria, was killed today in a massive bomb explosion that tore through his motorcade. At least nine other people were dead and 100 wounded in the blast.

At least 20 cars were set on fire in a blast that devastated the front of the famous St. George Hotel, blowing off balconies, and damaged a British bank and the Phoenicia Hotel along the Mediterranean waterfront.

Hariri moved toward the opposition camp after leaving office in October - in large part because of a dispute concerning Syria's controversial role in Lebanon. Hariri had rejected a Syrian-backed insistence that a rival politician, President Emile Lahoud, remain in office as president for a longer period.

Hariri has been in a rivalry with Lahoud for years.

Explosions in Beirut - while common during the 1975-90 civil war - have become rare since the conflict ended. In October, however, amid rising tensions between the government and opposition groups, a car bomb seriously injured an opposition politician and killed his driver in Beirut.