Three dead, 18 missing in US mudslide

Rescue workers are searching through mud and debris to find at least 18 people still unaccounted for in a mudslide that so far has claimed three lives.

The disaster in the northwest US state of Washington happened on Saturday, when the side of a mountain in Snohomish County suddenly slammed into the homes, highway and river below it.

At least 11 people are injured, including a six-month-old baby listed in critical condition, according to The Seattle Times newspaper.

Fire Chief Travis Hots, of the Snohomish County Fire District 21, said on Sunday at a press conference that the 18 reported missing were residents of neighbourhoods that were directly in the path of the mudslide, according to the Herald newspaper of Everett, Washington.

It is possible that people driving on Highway 530 have also been buried or washed away, Hots says.

The deep, unstable mud has made it extremely unsafe for rescuers, who had to give up a search on Saturday night to find someone yelling for help from a buried house.

Officials urged residents downstream along the Stillaguamish River to evacuate, out of concern that the water building up behind the unstable mud dam blocking the river could force through in a sudden flood.

About 100 rescuers are on the ground.

Geologists are also surveying the area from the air to see what can be done to stabilise things to protect rescue workers.