Rescue workers scrambled Saturday to find survivors and victims of the devastation wreaked by the worst floods to hit western Europe in living memory, which have already left at least 165 people dead and dozens more missing.

Western Germany has suffered the most brutal impact of the deluge that also pummelled Belgium, Luxembourg and the Netherlands, leaving streets and homes submerged in muddy water and isolating entire communities.

With the death toll in Germany at 141 into the fourth day of the disaster, authorities said more bodies were likely to be found in sodden cellars and collapsed homes. Some 22,000 rescuers have been mobilised.

In Germany's worst-hit states of North Rhine-Westphalia (NRW) and Rhineland-Palatinate, residents who fled the deluge were gradually returning to their homes and scenes of desolation.

Chancellor Angela Merkel is scheduled to visit the hard-hit town of Schuld in Rhineland-Palatinate on Sunday, her first trip to the flood zones since returning from a White House visit on Friday.

President Frank-Walter Steinmeier meanwhile was surveying the damage in Erftstadt in NRW on Saturday, where a landslide was triggered by the floods.

"We are mourning with all those who lost friends, acquaintances or family members," he said.

Soldiers could be seen wading waist-deep in muddy water in Erftstadt as they attempted to clear the streets and search for victims.

Many cars were still submerged, their doors flung open by those who managed to escape.

"We have broken highways, collapsed bridges, completely broken roads. It may be months, years before life in Erftstadt and the surrounding area resumes as we knew it," said Elmar Mettke, a spokesman for the local fire service.

At least 98 of the victims lived in the Ahrweiler district of Rhineland-Palatinate, Koblenz police said in an updated toll, including 12 residents of a home for the disabled who drowned in the rising waters.

In neighbouring Belgium, the death toll jumped to 24 with many people still missing.