Four people have been killed and eight are missing following the collapse of a highway tunnel under construction in southwestern China.
Water and mud burst from the tunnel as work was underway around 6 pm Tuesday in the Yunnan province city of Lincang, trapping 13 workers inside.
Authorities said five were pulled from the rubble, but only one of them survived and was hospitalised in stable condition.
Waterlogged and unstable conditions were complicating rescue work. Sniffer dogs and life detection machines have been deployed and a medical team is on standby at the site.
China suffers frequent industrial accidents despite efforts to improve safety training and inspections.
Last month, an underground car park under construction in southwest China collapsed, killing eight people.