People walk in the Park of the Fiftieth Anniversary in the snow in Brussels, Belgium, Jan. 17, 2024. (Xinhua)

BRUSSELS, Belgium -- Extreme weather conditions involving heavy snowfall and freezing rain hit many countries across Europe on Wednesday, causing flight cancellations and delays and disrupting road traffic.

In Belgium, departures from Brussels Airport in Zaventem were temporarily halted in the afternoon as the runways covered by snow need to be cleared. Most flights were delayed by about an hour and some got canceled, including flights to Frankfurt and Munich, the airport authorities said.

Heavy snow fell at noon in Brussels, causing traffic congestion on the Brussels Ring. Belgium's Transport En Commun network was also disrupted. In Liege and Charleroi, most buses were out of service on Wednesday.

The quarter-finals of the Belgian Cup, featuring Union Saint-Gilloise against Anderlecht and Oud-Heverlee Louvain against Antwerp, have been postponed by a week, the organizers of Pro League, the top league competition for association football clubs in Belgium, have said.

European Union flags are seen in the snow in Brussels, Belgium, Jan. 17, 2024. (Xinhua)

As a cold wave arrived in Belgium, the Royal Meteorological Institute forecast that temperatures will plummet to minus 10 degrees Celsius or lower later this week. It has issued a yellow alert for freezing rain and slippery road conditions in many parts of the country.

In the Netherlands, weather institute KNMI has also issued code yellow for many parts of the country due to snowy and slippery conditions.

Heavy snow has fallen in Limburg, a province in the southeast of the country, causing long traffic jams on highways, and local authorities have issued urgent calls on motorists to avoid the highways. Snowfall, up to 15 centimeters, is expected to continue in Limburg on Wednesday, said KNMI.

On Wednesday morning, Dutch traffic association ANWB reported 35 traffic jams covering 155 km of Dutch roads. During the day, trains running on the route between Utrecht and Sittard were reduced by half due to snowy conditions. Dozens of flights have been canceled or delayed at Schiphol Airport in Amsterdam.

In Luxembourg, all schools were closed on Wednesday, following a red alert for freezing rain and heavy snowfall declared by the national crisis unit on Tuesday. The government recommended that all residents should stay home "unless it is absolutely necessary to venture outdoors."

People walk on a road in Stockholm, Sweden on Jan. 17, 2024. (Xinhua)

Extreme weather conditions have also affected large parts of Germany, causing massive disruptions to road, air and rail traffic, and prompting school closures.

Germany's National Meteorological Service warned of "partly extreme weather conditions" across the central and southern regions with heavy snowfall that will continue into Thursday.

The country's largest airport in Frankfurt had to cancel more than 600 flights and all air traffic was halted at midday.

Local media reported that take-offs were canceled in Frankfurt because aircraft could no longer be safely de-iced, and the fully-packed ramps made landings impossible, too.

Munich Airport in the south of Germany anticipated around 254 flight cancellations, but about 410 take-offs and landings were still planned. "The winter operations mode is on so that one runway is always open for flight operations this morning," a spokesperson told Xinhua on Wednesday.

Rail operations were also restricted, with operator Deutsche Bahn warning of train cancellations and delays on regional and long-distance lines. As a "precautionary measure," the maximum speed of ICE high-speed trains was lowered to 200 kilometers per hour.

Snowfall and icy roads have caused accidents and traffic jams on many routes, with several injuries reported. A highway had to be completely closed off after a truck veered off the road and hit the crash barrier, according to German media reports.

In some districts and cities, classes were canceled from lunchtime and some schools were closed altogether.

Heavy snowfall also wreaked havoc in Northern Europe, prompting the closure of the main airport in Oslo on Wednesday afternoon. The Norwegian Meteorological Institute warned of "very heavy snowfall and strong winds" in the eastern coastal regions including Oslo, saying the extreme weather conditions are expected to persist.

Norway's railway operator Bane Nor has canceled all train services in eastern Norway until further notice. Public transport operator Ruter reported significant delays and cancellations affecting buses, trams, subways and ferries.

Swedish authorities also went on high alert due to a blizzard that was expected to hit most parts of the country on Wednesday afternoon. Heavy snowfall in the morning caused a jetliner to veer off the taxiway at the airport in Gothenburg and blocked many roads in the southwestern region.

Additionally, Swedish national rail company SJ has canceled many trains until the beginning of March due to heavy snowfalls and unusually cold weather this winter.

Since the beginning of January, Sweden has been hit by two blizzards and seen temperatures in the northern part of the country dropping below minus 40 degrees Celsius.