TAIYUAN, Nov. 19 (Xinhua) -- Fifteen people were killed and nine others injured in a coal mine gas explosion in northern China's Shanxi Province, local authorities said Tuesday.

Investigation showed that 35 miners were working underground at the coal mine in Pingyao County when the blast happened at 1:50 p.m. Monday, according to the Shanxi Administration of Coal Mine Safety. Eleven miners managed to escape.

"It is a production safety accident caused by production activity that broke the law and regulations, which reveals the problems of the involved company, such as lack of awareness of the rule of law and chaotic management," said Shen Xuping, director of the accident investigation division of the Shanxi Administration of Coal Mine Safety, at a press conference on Tuesday morning.

The cause of the accident is still being investigated, Shen said.

The nine injured miners mainly suffered from trauma and burns. They are in stable condition now, said Wang Guimei, director of the county's health bureau.

The county government has also dispatched 15 work teams to deal with the aftermath and compensation for the families of the 15 victims.