CHENGDU - Twelve miners were trapped when a coal mine flooded in Southwest China's Sichuan province Monday, local government officials said.

The flooding happened at around 10 am Monday when 30 miners were working underground at the Zengjiagou Coal Mine in the county of Dazhu, Dazhou city, according to a spokesman with the provincial work safety bureau.

Eighteen managed to escape while 12 others remained trapped, said the spokesman.

Rescue efforts are underway.