Authorities in the US state of Washington have found six more bodies after Saturday's huge landslide, bringing the number known to have been killed to 14, say police.

Three killed, 18 missing by landslide in Washington state

Officials now say as many as 176 people may remain unaccounted for after the 177ft (54m) wall of mud hit near the town of Oso, north of Seattle.

Search crews have worked day and night, using helicopters and laser imaging.

But officials admit they have little hope of finding survivors in the muck.

President Barack Obama has declared an emergency in Washington state and ordered federal authorities to co-ordinate the disaster relief effort.

Speaking earlier after surveying the area from the air, Washington Governor Jay Inslee said it was "devastation beyond imagination".

He said the slide "basically cut a mountain in two" and deposited it on the town below. Nothing in the path of the slide was still standing.

"It's that absolute devastation that causes us all real pain," he said.

Half a town gone

At a new conference on Monday evening, Snohomish County emergency management director John Pennington said the official list of the missing stood at 176.

But he said he did not think the final death toll would be so high, because some of those listed as unaccounted for would be found to be alive, and other names would prove to be duplicates.

But he said authorities no longer expected to find survivors in the debris.

"We as a community, we as a county, are beginning to realise that we are moving toward a recovery operation," he said.

"There is an awful lot of grieving."

The landslide left behind a cliff known as a head scarp 183m high, Washington state geologist Dave Norman told reporters on Monday afternoon.

"This is one of the biggest landslides I've seen," Mr Norman said.

Authorities have continued their search-and-rescue operations amid a tangled, water-logged field of muck and debris, using rescue dogs, aerial photography and laser imaging to aide the search.

Stable

Officials said the conditions were treacherous, and the threat of further landslides on Monday forced the authorities to pull search-and-rescue workers back from the scene briefly until scientists determined there was no further risk.

"Right now it's stable, it's in good shape, and the good news is the rescue can continue," said Steve Tomsen, Snohomish County public works director.

More than 30 homes were destroyed and more than half the town of Oso is missing - a recent census put its population at 180.

The landslide cut off the city of Darrington and clogged the north fork of the Stillaguamish River.

Mr Norman said the river had begun to flow over the debris, relieving the water pressure in the part of the river blocked behind the landslide and lessening the chances of a catastrophic flood if the water should break through all at once.

The authorities say the landslide was caused by recent heavy rain, although Mr Norman said the area's terrain was made up of unstable glacial sediment and had been subject to landslides since the last ice age.

He said landslides occurred in the area in 2006 and 1969.

Source: BBC