NANCHANG, Feb. 28 -- The number of miners trapped after a coal and gas outburst at a colliery in east China's Jiangxi Province Saturday rose to four, said local authorities on Saturday night.

The accident happened at around 11:57 a.m. at Yongshan coal mine in Leping, a county-level city, the provincial coal mine safety watchdog said. An initial report says three miners were trapped.

Rescue team is clearing the passageway clogged by coal cinder to search for those trapped.

The cause of the accident is under investigation.