Heavy flooding in Germany has left at least 33 people dead and dozens others missing, regional officials said, as rising waters swept away cars and caused some buildings to collapse on Thursday.

Storms across parts of western Europe in recent days caused rivers and reservoirs to burst their banks, resulting in flash floods as rain-soaked soil failed to absorb any more water. Authorities in the western German region of Euskirchen said Thursday that eight deaths had been reported there in connection with the floods. Rescue operations were hampered by the fact that phone and internet connections were down in parts of the county, which is southwest of Cologne.

Rhineland-Palatinate and North Rhine-Westphalia (NRW) states were the worst hit by the unusually heavy rainfall, which has caused rivers to burst their banks and threatens to bring down more homes.

Police in the western city of Koblenz said 18 people had died in Ahrweiler county. Up to 70 people were reported missing after several houses collapsed overnight in the village of Schuld in the Eifel, a volcanic region of rolling hills and small valleys southwest of Cologne.

Dozens more were trapped on the roofs of their houses awaiting rescue. Authorities used inflatable boats and helicopters, and the German army deployed 200 soldiers to assist in the rescue operation.

The chief of NRW state Malu Dreyer described the flooding as a "catastrophe."

"There are dead, missing and many people still in danger," she said in the remarks to BBC News. "All of our emergency services are in action round the clock and risking their own lives."

The full extent of the damage in the region was still unclear after many villages were cut off by floodwater and landslides that made roads impassable. Videos posted on social media showed cars floating down streets and houses partly collapsed in some places.

Video footage from Bad Neuenahr, which is about 60 kilometers (37.28 miles) northwest of Koblenz, showed cars and trucks strewn across the streets. The road was blocked by debris and fallen trees after the floodwaters receded.

Authorities have declared an emergency in the region after days of heavy rainfall that also affected large parts of western and central Germany, as well as neighboring countries, causing widespread damage.

Police said two men, aged 77 and 82, died after their basements were flooded in the western cities of Kamen and Wuppertal, where authorities warned that a dam threatened to burst.

Authorities in the Rhine-Sieg county south of Cologne ordered the evacuation of several villages below the Steinbachtal reservoir amid fears the dam there could also break.

A firefighter drowned Wednesday during rescue work in the western German town of Altena and another collapsed during rescue operations at a power plant in Werdohl-Elverlingsen. One man was missing in the eastern town of Joehstadt after disappearing while trying to secure his property from rising waters, authorities said.

According to the German Weather Service (DWD) massive rainstorms are expected in southwestern Germany on Thursday.

Rail connections were suspended in large parts of North-Rhine Westphalia, Germany's most populous state. Gov. Armin Laschet, who is running to succeed Angela Merkel as chancellor in this fall's German election, was expected to visit the flood-hit city of Hagen later Thursday.

"I am shocked by the catastrophe that so many people in the flood areas have to endure," Merkel said in a tweet sent by her press spokesman. "My sympathy goes to the families of the dead and missing," she added.

"To the many tireless helpers and emergency workers, I thank you from the bottom of my heart."

Relentless rains through the night worsened the flooding conditions in eastern Belgium, where one person was reported drowned and at least another was missing. Some towns saw water levels rise to unprecedented levels and had their centers turned into gushing rivers.

Major highways were inundated and in the south and east of the nation, the railway service said all traffic was stopped, adding that "alternative transport is highly unlikely."

In eastern Eupen, on the German border, one man was reported dead after he was swept away by a torrent, a local governor told RTBf network.

In Liege, the main city in eastern Belgium, the Meuse river could break its banks by early afternoon and spill into the heart of the city. Police warned the citizens to take precautionary measures.

Authorities in the southern Dutch town of Valkenburg, close to the German and Belgian borders, evacuated a care home and a hospice overnight amid flooding that turned the tourist town’s main street into a river, Dutch media reported.

The Dutch government sent some 70 troops to the southern province of Limburg late Wednesday to help with tasks including transporting evacuees and filling sandbags as rivers burst their banks. There were no reports of injuries linked to flooding in the Netherlands.

Unusually intense rains have also inundated a swath of northeast France this week, downing trees and forcing the closure of dozens of roads. A train route to Luxembourg was disrupted, and firefighters evacuated dozens of people from homes near the Luxembourg and German border and in the Marne region, according to local broadcaster France Bleu.

The equivalent of two months of rain has fallen on some areas in the last one or two days, according to the French national weather service. With the ground already saturated, the service forecast more downpours Thursday and issued flood warnings for 10 regions.