Flash floods triggered by cloudbursts in the mountainous northwest have brought destruction since Friday in the worst spell of this year's monsoon.

Pakistan has received higher-than-normal monsoon rainfall this year, triggering floods and mudslides that have killed more than 540 people since June 26.

Rescuers and residents resumed searching on Tuesday for survivors as the death toll from five days of torrential rain rose to almost 400, with authorities warning monsoon downpours would continue until the weekend.