Spanish emergency services say an explosion at a biodiesel plant has killed two people and left one survivor seriously injured.

The Emergency Coordination and Information Center for the regional government of Valencia says the explosion occurred at around 11 a.m. Saturday at a fuel production plant in Algemesi, 33 kilometers (21 miles) south of the port city of Valencia.

The service says three ambulances, a government helicopter and firefighters are attending the scene and police have begun an investigation into the cause of the blast.

Photographs posted on the center's Twitter account show plumes of black smoke emerging from a factory building.