At least six workers have been trapped for more than nine hours after a tunnel under construction collapsed in south China's Sanya City, Hainan Province, the tunnel constructor said on Friday.

The accident occurred at about 11:30 PM on Thursday in the Yingbin Tunnel on the expressway circling Sanya City, said Gao Ya, who is with Changsha Road and Bridge Construction Company and in charge of the project.

The accident site is about 150 meters from the entrance of the tunnel with its current bore extending more than 1,000 meters.

Wang Yong, Sanya's mayor, was at the scene directing the rescue work of more than 100 firefighters, police and medical staff. Two excavators and one loader were clearing the site.

The six trapped workers could not be contacted.

(Xinhua News Agency June 5, 2009)