Five dead and multiple casualties in 'hydrogen' explosion at Japanese chemical factory

At least five people have been killed in an explosion at a chemical factory in central Japan, according to news reports.

Fire department officials said 17 people were injured in the blast at metal and chemical company Mitsubishi Materials Corp's Yokkaichi plant during maintenance on Thursday afternoon.

Police have put the death toll at two but Japanese media say five people have died and the condition of those in hospital is not known.

Mie prefecture police said investigators believed that a hydrogen explosion was caused by a chemical reaction when plant workers were rinsing heat exchange equipment at a silicone plant.

The complex is in Yokkaichi City, about 220 miles west of Tokyo.

The city is a manufacturing centre that produces porcelain, cares, cotton, chemicals, tea, cement and computer parts.

Mitsubishi Materials Corp specialises in cement, metals, tools, electronics and recycling.

It is part of the Mitsubishi Group – one of the largest multinationals in the world.

Additional reporting by Associated Press