BEIJING (Reuters) - Chinese authorities have dispatched rescue workers to save miners trapped after an accident at a coal mine in the eastern province of Shandong late on Saturday, Chinese state media reported on Sunday.

A rock burst at around 11 p.m. (1500 GMT) on Saturday destroyed part of a water drainage tunnel in the coal mine, killing two and trapping another 20 workers, the official Xinhua news agency reported. The mine is owned by Shandong Energy Group Co Ltd and located in the province’s Yuncheng County, the report said.

Xinhua separately published on its official social networking services account images of a miner who was rescued from the mine earlier on Sunday.

The cause of the accident was still under investigation, Xinhua said, adding that the dangerous conditions at the mine are hampering the rescue efforts. More than 170 rescue workers are at the site, Xinhua said.