QINGDAO - Three people were killed and six injured in a shipyard explosion Tuesday afternoon in East China's Shandong province, local authorities said.

The explosion happened at around 2:50 pm Tuesday when workers were repairing ships on a floating dock at the Dongfeng Shipyard in Laoshan District of coastal city Qingdao, the district's government officials said.

Three fishermen who were on a boat near the site of the explosion died in hospital after treatments failed, while those who were injured are shipyard workers, officials said.

The six injured workers are being treated in hospital and their injuries are not life-threatening, doctors said.

The blast broke windows and light bulbs in a restaurant located 300 meters away from the dock, said the restaurant owner.

Meanwhile, nearby villagers said windows at their homes also shattered.

Police are investigating the incident.