Four workers were trapped in a coal mine in Xingyang City of central China's Henan Province after gas leaked in the mine around 4 a.m. on Monday, according to the local government.

Rescuers said that so far they have not found any sign of the four workers, who are from the Kaiyuan Colliery at the city's Liuhe Town.

The local government has set up a rescue team, comprised of officials from the public security, health and work safety supervision departments.

The cause of the gas leak is being investigated and rescue work is underway.

Source: Xinhua