ISLAMABAD, Nov. 15 (Xinhua) -- At least six people were killed in an explosion in Pakistan's southern port city of Karachi late Wednesday, local media and police said Thursday.

Local media quoted hospital officials as saying that the seriously wounded people died during their treatment because 90 percent of their bodies had severe burn wounds.

Another worker who also got serious injuries was under intensive care in a hospital of the city.

A local police official said the boiler blast occurred in a factory belonged to Honda Atlas, a joint venture of Honda Motor and Atlas Group, near Landhi Manzil area of Karachi, the capital of southern Sindh province.

Chief Minister of Sindh Syed Murad Ali Shah took notice of the incident and ordered an investigation into the reasons behind the explosion.

Police told media that an initial probe revealed that the explosion occurred due to poor maintenance and gas leakage, adding that there were no proper arrangements to handle the emergency in the factory.

A case would be registered against the factory owners over accidental deaths of the workers.