HARBIN -- A total of 17 people are trapped underground in a coal mine accident Thursday in Northeast China's Heilongjiang province.

The cage fell as the cable caught fire at Dongrong Second Mine of the Shuangyashan branch company of the Longmay Mining Holding Group and a total of 256 miners have been saved out of the mine, according to local authority.

Casualties remain unknown.

Rescuers are cleaning up the wirerope and other stuff under the cage to prepare for breaking into the cage to rescue the trapped.

An investigation of the accident is underway.