The death toll from flash floods that swept away entire villages in the southern Philippines has climbed to nearly 1500, as authorities widen their search for bodies.

The Office of Civil Defence's latest tally on Tuesday listed 891 dead in Cagayan de Oro and an additional 451 in nearby Iligan city. The rest came from several other provinces. Most of the dead are unidentified.

Damaged vehicles washed away by flash floodsfrom Typhoon Washi lie in a ditch in Cagayan de Oro, southern Philippines. Credit:Reuters

"The search will continue as long as we are recovering bodies," said Civil Defence head Benito Ramos.

He said that decomposing remains were retrieved floating in the sea as far as 100 kilometres from the two cities where a Dec 16 tropical storm unleashed more than a month's worth of rainfall in 12 hours, sending walls of water gushing into homes.