Two people were killed and nine others remain trapped in a roof collapse at a polymetallic mine in south China's Guangxi Zhuang Autonomous Region, local authorities said Tuesday.

The accident happened around 6:30 p.m. Monday at an ore field in Daping Village of Nandan County. The mine where the roof caving occurred belongs to a local mining company.

An initial investigation showed that 11 people were trapped, including the two people who were found dead, said the publicity department of Nandan County.

The shaft where the accident occurred measures 3.7 km deep. The high temperature and inferior air quality at the site of the accident have caused difficulty for the rescue work.

So far, rescue facilities and supplies have been sent into the shaft. Rescue work is ongoing.