NANJING - Three people were killed and 12 others injured, including one seriously, in a shipyard blast Sunday in East China's Jiangsu province, according to local authorities.

The accident occurred at around 2 pm on a ship, which was under construction at the Wujiazui shipyard in Nanjing, the capital city of Jiangsu.

The explosion was triggered by sparks in a space with combustible gas during the construction, local work safety watchdog said after an initial investigation.

The injured workers were sent to local hospitals, and the injuries to the seriously wounded one were not life-threatening, sources said.

A further investigation into the accident is under way.