BRUSSELS, July 17, 2021 (BSS/AFP) - Belgium's Prime Minister Alexander de Croo on Saturday headed for the scene of what he has branded "unprecedented" flood damage, as officials warned the death toll would increase.

De Croo was to be joined by European Commission president Ursula von der Leyen in the river valleys of eastern Belgium near the border with her native Germany, also badly hit.

The last official death toll on Friday night was 20, with up to 20 people still missing, and police in Angleur near Liege said they had found at least one more body overnight.

A crisis centre spokesman said a new official figure would be given later in the day, but confirmed that it was rising.

The floods descended on densely inhabited valleys in the Meuse region on Thursday after days of intense rain.

By Saturday, the skies were clearing and the downpour had abated, but the retreating waters left scenes of devastation across 120 local government areas.

Police were going door to door, checking on residents, and De Croo has declared Tuesday -- the eve of Belgium's national day -- a day of official mourning.