South Korean shipyard explosion kills four

SEOUL—Four South Korean workers were killed Friday in an explosion at a shipyard in the southeastern city of Ulsan, police said.

Police said an oxygen-fuelled cutting machine might have caused the explosion at Sejin Heavy Industries, a ship components maker. They said an investigation was under way to determine the cause of the blast.

At the time of the explosion, the four people were working in the cabin of a 4,200-ton vessel, Yonhap news agency said.

The explosion was probably caused by sparks from the cutting machine, it said.