London's complex transportation system ground to a halt on Monday after the city saw its most significant snowstorm in 18 years.

After receiving 10 centimetres of snow overnight and another 10 centimetres on Monday afternoon, the capital city was finding it hard to cope.

The city's five airports all briefly shut down at one time or another, with some 800 flights cancelled throughout the day.

There were no London buses out on city roads for much of the day, and the many cars that took to the roads in their absence ended up in traffic jams, some caused by a spike in car accidents.

Mayor Boris Johnson said there was concern that the buses, if put into service, could become "a lethal weapon" if they skidded on roads.

Many schools, courts and stores stayed closed throughout the day, and some hospitals were working with a reduced staff presence.

"We're not in Russia here," Guy Pitt, a Transport for London spokesman told The Associated Press. "We don't have an infrastructure built for constant snow."

Former mayor Ken Livingstone criticized Johnson, saying the incumbent mayor had plenty of time to prepare for the storm because it had been predicted late last week.

"There has never been a day where the bus service has been cancelled for bad weather. Not in 100 years," he told the BBC.

Meanwhile, the city's subway network was also badly affected because much of the system is above ground. Many of the tracks were covered in snow or ice and some of the operators themselves were unable to make it into work.

"We are doing everything in our power to ensure that the services -- road, rail and airports -- are open as quickly as possible and we are continuously monitoring this throughout the day," Prime Minister Gordon Brown said Monday.

CTV's London Bureau Chief Tom Kennedy said the city has been "largely paralyzed."

"If they were used to this kind of thing it would be fairly simple but I've been watching this story for about 6 to 8 hours and I haven't seen a single snow plow yet," Kennedy said Friday.

"There are no trucks out salting the roads. They just don't have the infrastructure and the weather culture here to deal with this kind of thing."

The weather also caused problems for airports in Ireland and France, where residents dealt with icy roads and cancelled flights.

With files from The Associated Press