The explosion took place early Tuesday on the Baalbek road between Sbouba, where Hizballah maintains a base, and Wadi Abu Moussa in eastern Lebanon when Hizballah members opened fire on a suspect four-wheeler vehicle. It exploded either from the gunfire or was detonated by the driver. Ambulances headed toward the scene to collect an unknown number of casualties. After deadly car bomb attacks in its Beirut strongholds, Hizballah has been on the lookout for more bomb cars known to be heading its way.