ZHENGZHOU, March 25 -- The 13 miners trapped underground after a colliery gas burst on Friday in central China's Henan Province were all confirmed dead on Tuesday night.

Their bodies had all been found by 9:30 p.m., according to the rescue headquarters.

The outburst happened at 10:37 a.m. on Friday in a 500-meter-deep tunnel at a coal mine in Ruzhou City, where 16 miners were working underground. Three managed to escape.

The coal mine belongs to the Changhong Mining Company Limited, an affiliated company of the state-owned China Pingmei Shenma Group.

The cause of the accident is under investigation.