HARBIN -?Nine people were killed in coal mine gas explosion in northeast China's Heilongjiang Province Wednesday afternoon, local authorities said Thursday.

The explosion occurred at about 2:40 p.m. Wednesday at the Yuchen coal mine in Jidong County, the county government said.

At the time of the blast, 17 miners were working underground. Of them, eight were rescued and rushed to hospital. They are in stable conditions.

Bodies of the rest nine miners have been lifted to the ground.

An investigation into the cause of the explosion is under way.