BERLIN (AP)—More than 120 people have died in devastating floods across parts of western Germany and Belgium, officials said Friday, as search and rescue operations continued for hundreds more still unaccounted for or in danger.

Authorities in the German state of Rhineland-Palatinate said 60 people had died there, including 12 residents of an assisted living facility for people with disabilities in the town of Sinzig who were surprised by a sudden rush of water from the nearby river Ahr. In neighboring North Rhine-Westphalia state officials put the death toll at 43, but warned that the figure could increase.

German President Frank-Walter Steinmeier said he was “stunned” by the devastation caused by the flooding and pledged support to the families of those killed and to cities and towns facing significant damage.

“In the hour of need, our country stands together,” Mr. Steinmeier said in a statement Friday afternoon. “It’s important that we show solidarity for those from whom the flood has taken everything.”

Rescuers rushed Friday to help people trapped in their homes in the town of Erftstadt, southwest of Cologne. Regional authorities said several people had died after their houses collapsed when the ground beneath them sank suddenly. Aerial photos showed what appeared to be a massive sinkhole.

“We managed to get 50 people out of their houses last night,” county administrator Frank Rock said. “We know of 15 people who still need to be rescued.”

Speaking to German broadcaster n-tv, Mr. Rock said that authorities had no precise number yet for how many had died.

“One has to assume that under the circumstances some people didn’t manage to escape” he said.

Authorities said late Thursday that about 1,300 people in Germany were listed as missing, but they cautioned that the high number could be due to duplicated reports and difficulties reaching people because of disrupted roads and phone service.

After Germany, where more than 100 people have died, Belgium was the hardest hit by the floods that caused homes to be ripped away and roads to be turned into wild rivers. Belgian Interior Minister Annelies Verlinden told VRT network Friday that the country’s official confirmed death toll has grown to 18. The number of missing is estimated at 19.

Water levels on the Meuse river that runs from Belgium into the Netherlands remains critical, and several dikes are at risk of collapsing, Ms. Verlinden said. Authorities in the southern Dutch town of Venlo evacuated some 200 hospital patients due to the looming threat of flooding from the river.

Flash floods this week followed days of heavy rainfall in Western Europe which turned streams and streets into raging torrents that swept away cars and caused houses to collapse across the region.

Thousands of people remained homeless in Germany after their houses were destroyed or deemed at-risk by authorities, including several villages around the Steinbach reservoir that experts say could collapse under the weight of the floods.

Defense Ministry spokesman Arne Collatz said the German military had deployed over 850 troops as of Friday morning, but the number is “rising significantly because the need is growing.” He said the ministry had triggered a “military disaster alarm,” a technical move that essentially decentralizes decisions on using equipment to commanders on the ground.

Italy sent a team of civil protection officials and firefighters, as well as rescue dinghies, to Belgium to help in the search for missing people from the devastating floods.

The firefighters tweeted a photo of one team working in Tillf, south of Liege, to help evacuate residents of a home who were trapped by the rising waters.

In the southern Dutch province of Limburg, which also has been hit hard by flooding, troops piled sandbags to strengthen a 0.7-mile stretch of dike along the Maas river and police helped evacuate some low-lying neighborhoods.

Caretaker Prime Minister Mark Rutte said Thursday night that the government was officially declaring flood-hit regions a disaster area, meaning businesses and residents are eligible for compensation for damage.

Dutch King Willem-Alexander visited the region Thursday night and called the scenes “heart-breaking.”

Meanwhile, sustained rainfall in Switzerland has caused several rivers and lakes to break their banks. Public broadcaster SRF reported that a flash flood swept away cars, flooded basements and destroyed small bridges in the northern villages of Schleitheim und Beggingen late Thursday.

Erik Schulz, the mayor of the hard-hit German city of Hagen, about 31 miles northeast of Cologne, said there had been a wave of solidarity from other regions and ordinary citizens to help those affected by the devastating floods.

“We have many, many citizens saying ‘I can offer a place to stay, where can I go to help, where can I registered, where can I bring my shovel and bucket?’,” he told n-tv. “The city is standing together and you can feel that.”