(CNN) -- A gas explosion Friday night at a northeastern Chinese coal mine killed 28 people, China's state-run Xinhua news agency reported.
Thirteen people were rescued after the blast, which happened around 10:40 p.m. (10:40 a.m. ET), a spokesman with the provincial work safety and supervision bureau told Xinhua.
Their injuries are not considered life-threatening, the spokesman said.
The incident occurred at the Babao Coal Mine in the city of Baishan, which is part of Jilin province near the North Korea border.
The rescue effort was finished by mid-Saturday morning, the spokesman said.
At that point, the cause of the explosion was still under investigation.
According to Xinhua, the affected mine is state-owned under the Tonghua Mining group.