Two people were killed and another seriously injured in an explosion in a biodiesel plant in the town of Algemesi in east Spain on Saturday.The explosion occurred around 11:00 a.m. local time in an industrial estate on the outskirts of Algemesi, 33 km south of Spanish port city Valencia, Xinhua reported.The injured person had burns on 80 percent of his body.The cause of the explosion is not known yet. Some believe the accident could be caused by people soldering a storage silo, which contained residual flammable gas.