GUIYANG - Four people have been confirmed dead after a coal mine blast Thursday afternoon in Southwest China's Guizhou province, local authorities said on Friday.

The accident happened at 4:15 pm at the Zheyan Coal Mine in Gaoshi township in the city of Fuquan when 49 people were working underground, according to the city's publicity department.

Forty-five people managed to escape while four others were trapped in the shaft, the department said.

Rescue work continued until the bodies of the four trapped were recovered early Friday morning.

An investigation into the cause of the blast is under way.