Four people have been killed and three others are missing after an Indian oil tanker anchored at the coast of east China's Zhejiang Province exploded and caught fire on Tuesday. The explosion happened on Tuesday morning when seven workers were repairing the tanker off Daishan County in the city of Zhoushan, said a spokesman with the city government. As of noon time, the fire had been put out and rescuers were still searching for the three missing people, said the spokesman. The identities of the victims are not available yet. The cause of the accident is under investigation.