The number of people missing after a mudslide devastated a tiny community in Washington state has fallen sharply.Many of the 90 residents of Oso who were feared to have been caught up in the disaster have since been found safe.

Search teams continue to hunt for 30 people who may be buried beneath the rubble.

It comes as the number of people confirmed dead by the medical examiner’s office rose by one to 18.

Rescuers, who have located one additional victim in the debris field, face a harrowing search for further victims.

Jason Biermann, program manager at the Snohomish County Department of Emergency Management, said: “Due to the destructive nature of the mudslide, they’re often making only partial recoveries.

“That is a challenge for the medical examiner’s office as they attempt to identify bodies.”

The mudslide flattened many objects in its path, levelling homes and trees and leaving much of Oso, about 55 miles (90km) north of Seattle, unrecognisable.

A 50-metre wall of mud crashed into the town when part of a rain-soaked hillside collapsed on March 22.