Four people were killed and at least six others were injured after a truck loaded with gunpowder exploded Saturday in central China"s Hubei Province, Xinhua reported. The accident happened at about 00:20 a.m. at a section of the Beijing-Zhuhai Highway in Xiaogan City. Four died and six were injured, including one seriously, at the scene, a Xiaogan municipal government spokesman said. The explosion destroyed three vehicles nearby and damaged the road surface. It also damaged some houses in a nearby village and injured at least 20 villagers, he said. "The longest crack on the road is more than 10 meters and the deepest is one meter. More than 700 square meters of road surface were destroyed," said Zhang Liang, an official with the Hubei Beijing-Zhuhai Highway Administration Office. The cause of the accident is being investigated. --SPA