Rescuers have pumped out water to try to find 14 construction workers trapped by a flood in a highway tunnel being built in southern China.
The rescuers had not been able to contact the workers missing since the flood about 3.30am on Thursday, the Zhuhai city emergency management department said in an online post.
"Rescue work is proceeding in an intense and orderly way," it said.
Workers were about one kilometre from the entrance to the tunnel when a strange noise was heard and material started falling from the top of the tunnel, Yan Dawu, the deputy general manager of the construction company, said at a news conference.
An evacuation was ordered, but water gushed in and 14 people were unable to get out, Yan said. "We feel deeply guilty and deeply blame ourselves," he said.
The area where they were working is under a reservoir. By 12.30pm, rescue teams had plugged the hole where water was coming in. They were draining and pumping water from the reservoir as well as from the tunnel.
More than 1000 workers, 22 fire trucks and five pumping vehicles were taking part in the effort, with search and rescue teams dispatched from surrounding cities in Guangdong province.
In March, two workers died in another part of the tunnel when a protective wall collapsed and they were hit by falling stones, according to a notice from the Zhuhai emergency management department.