Washington state search and rescue crews have located six more bodies, bringing the total number of confirmed dead to 14 in the massive mudslide that struck a rural community in Snohomish County Saturday morning.

Snohomish Country emergency management director John Pennington, says the number of people reported missing has also jumped from 108 to 176.

'The 176 is a number I believe very strongly that you're not going to see in fatalities'- Emergency management director John Pennington

But Pennington says the higher number is  due to officials actively soliciting information, much of which consisted of vague descriptions of individuals that could easily be duplicates.

"The 176 is a number I believe very strongly that you're not going to see in fatalities," said Pennington. "I believe it's going to drop dramatically. Why did it increase today? Because we were successful in pulling in the information. It's as simple as that."

The search today was temporarily halted when rescuers were pulled back after the debris field was deemed unstable.

The 2.6-square-kilometre slide destroyed about 49 structures when a wall of mud and debris swept across 1.5 kilometres of State Route 530 near the community of Oso, about 88 kilometres north of Seattle and roughly 200 kilometres southeast of Vancouver.

Snohomish County spokesman John Pennington said early Monday that officials worked non-stop Sunday night to consolidate reports of missing people collected by various agencies and came up with a list of 108 individuals.

He stressed that it was a "soft 108" and represents all the reports received by various agencies, that some reports are vague — like "Frank" or "John with brown hair" — and that there may be duplicates in the list.

"We have 108 individual names, or individual identities," he said. "The number is, I think, no questions, going to decline dramatically... but it's what we're working with."

Pennington said there were also 108 lots that were examined in the area of the slide.

Records show that only 49 of those properties were known to have structures of some kind on them.

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Brian Anderson and Coby Young search through the wreckage of a home belonging to the Kuntz family. (Genna Martin/The Herald/Facebook)

Of those, 25 were permanent homes, 10 were part-time or vacation homes, 13 were trailers or RVs, and one was a cabin.

Pennington said there may also be additional people missing who have not been reported, as there were reports of contractors and other workers being in the area and there were also likely drivers on the stretch of Route 530 that was buried.

Members of the public who could be on that list are asked to check in with the emergency call centre at 1-425-388-5088.

No survivors found

Search and rescue teams took to the air in helicopters and the ground on foot on Sunday looking for anyone who might still be alive, but hope of finding any more survivors from the massive mudslide waned as crews worked through the night and all day Monday.

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A four-year-old is rescued from the mudslide field near Oso, Wash., on Saturday. His pants came off as the aircrew struggled to get him free from the mud. The hands of another rescued person can be seen in the lower right hand corner of the frame. (Central Pierce Fire & Rescue/Facebook)

"We didn't see or hear any signs of life out there today," Snohomish County Fire District 21 Chief Travis Hots said. "It's very disappointing to all emergency responders on scene."

Authorities believe the slide was caused by ground made unstable by recent heavy rainfall.

Washington Gov. Jay Inslee described the scene as "a square mile of total devastation" after flying over the disaster area midday Sunday. He assured families that everything was being done to find their missing loved ones.

The area has a history of unstable land, and was the site of a smaller slide in 2006.

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Some cars were crushed into small pieces by the mudslide. Searchers said they had trouble seeing people from the air, as they were covered in mud and blended in with the surroundings. (Central Pierce Fire & Rescue/Facebook)

Pennington said Saturday's slide happened without warning.

"This slide came out of nowhere," he said.

The slide also blocked the North Fork of the Stillaguamish River.

With the water pooling behind the debris, authorities worried about downstream flooding and issued an evacuation notice overnight Saturday and overnight Sunday.

The water had begun to seep through the blockage Sunday afternoon, alleviating some concerns, but the National Weather Service issued a flash flood watch for Snohomish County through Monday afternoon.

Snohomish County officials said Sunday and Monday that residents could return home during daylight hours. Even though the evacuation had been lifted, Inslee urged residents to remain alert.

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An aerial photo taken Sunday shows a house partially submerged by the backup of the Stillaguamish River behind the mudslide debris dam. (Office of Jay Inslee/Flickr)

Pennington said Monday that the water behind the debris dam was continuing to back up along the north fork of the Stillaguamish.

Seven homes were reported to be flooded, some of the houses had water up to the eaves.

"The bad news is that the water continues to rise," Pennington said.

"If there is a silver lining in that event, and it is tragic because it is people's homes, it is that it is a slow, methodical rise. You can see that danger."

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Move the slider across the images to see the before and after of the Snohomish mudslide. On mobile touch left or right side of image for slider movement.

Map: Oso, Washington mudslide

With files from The Associated Press