CHENGDU - Two miners injured in a colliery gas explosion Friday in southwest China's Sichuan province died on the way to hospital, bringing the death toll from the accident to 13, local authorities said Saturday.

Treatment is being given to eight other people injured in the blast, four of whom are in a critical condition, according to a press release issued by the provincial work safety administration.

By noon on Saturday, one person was still missing and rescue work was continuing, said the press release.

The accident happened at 1:20 p.m. Friday at Diaoyutai Coal Mine in Junlian county, in the city of Yibin.

Its cause is under investigation.