Drivers were urged to take extra care tonight after snow and ice brought mayhem to the roads of Sussex.

Overnight sleet, snow and rain turned roads into ice rinks, caused a string of accidents and brought some major roads to a rush-hour standstill.

Police said this afternoon that all major routes across the county were now clear. A spokeswoman said: "The weather seems to have subsided for the time being.

"However, we urge people if they have to go out to leave extra time for their journeys and drive extremely slowly and carefully at all times. Some roads are still very dangerous."

Rush-hour drivers faced massive delays this morning after parts of some roads were closed and accidents or breakdowns blocked others.

Five people were hurt when two buses and a police car crashed on black ice in Palmeira Square, Hove. They had minor head, neck and leg injuries.

Another bus hit traffic lights at the junction of Old Steine and North Street, Brighton, leaving one man with a minor back injury.

The A27 was closed in both directions at its junction with the A23 near Brighton because heavy lorries were sliding downhill backwards. The A271 was closed for a time because of sheet ice.

Parts of Hollingbury, Withdean and Westdene were cut off as drivers abandoned their cars on hills. Buses were diverted and routes cancelled.

Brighton and Hove Bus and Coach Company was unable to run buses in some residential areas including Mile Oak, Westdene, parts of Hangleton, parts of Saltdean and Woodingdean.

A burst water main at the Norfolk Bridge in Shoreham led to major delays on the A259 in both directions.

The runway at Gatwick Airport was closed for about 45 minutes while it was cleared of snow. It reopened just after 7.30am.

A spokesman for West Sussex County Council said the conditions had taken the authority by surprise.

He said: "We were gritting for snow but the problem was that before the snow fell there was a belt of rain which was not forecast. That tended to wash the gritting away, meaning we had to go out again."

The spokesman said gritting had taken place on major roads across the county from 6pm last night and many were re-gritted in the morning.

Nick Chambers of Polegate traffic police said: "The gritters are out but the slush is freezing and making the roads very dangerous.

"As usual, we are asking people not to make unnecessary journeys. The situation will get even worse if it freezes again overnight."