CHENGDU - The death toll from a gas blast on Thursday in Southwest China's Sichuan province rose to two after an injured person died in hospital, local authorities said Friday.

A 30-year-old man died at 8:50 pm Thursday, following the death of a 44-year-old woman earlier that day despite receiving medical attention, according to a statement issued by the Nanjiang county government.

The 24 injured were still receiving treatment at two local hospitals, and two of them were in critical condition.

The accident occurred around 3 pm Thursday on the second floor of an eight-story building belonging to the China Mobile branch in the county, the statement said.

An initial investigation indicated that the blast was caused by a natural gas leak in a kitchen.

A further investigation into the cause of the leak is underway.