Sana'a, Yemen  - Six workers were injured after an explosion rocked a steel plant in the southern Yemeni port city of Aden at midnight Thursday, state news agency Saba reported.

The agency said the explosion occurred in a steel mill furnace at the Bazaraa plant in Aden, some 360 kilometres from the capital Sana'a. It said the furnace was utilized for recycling iron.

It quoted a municipal source in Aden as saying that six injured workers were rushed to hospital and treated for burns. Three were discharged after receiving treatment, while three others remained in critical condition.

Police initiated an investigation to find out the cause of the blast, according to the agency.

The extent of the damage to the plant was not immediately clear. (dpa)