Riot police with dogs, batons and shields have clashed with hundreds of people throwing bangers, bottles and chairs after an alleged illegal rave in central London.

The trouble erupted last night on Halloween as hundreds of people gathered on a street at Albert Embankment.

Police battled the crowd there for over two hours.

Describing the scene, one witness said: "It was mayhem. There was traffic chaos as police blocked the road."

The crowd appeared to disperse around 12.20am but the disorder continued as people moved down Lambeth Road on to Lambeth High Street and nearby Whitgift Street.

Police said they had posted officers at junctions to nearby Whitgift Street to "to prevent any escalation" of the trouble.

Local police tweeted: "We are dealing with a public disorder on Whitgift Street. We have officers positioned at respective junctions to prevent any escalation.

"We have public order trained officers and police dogs at the scene."

As police formed a line against the crowd on Whitgift Street at around 2am, objects including chairs and bottles were thrown at them.

No officers were seriously injured, but four are understood to have been treated for injuries at the scene.

A number of arrests have been made, the Met Police said.

An event called Scumoween: A Nightmare On Scum Street had been advertised on Facebook to take place in Whitgift Street beginning at 8pm last night and continuing all weekend.

Of 13,000 invited guests on the social networking site, 4,000 said they were planning on attending.

In a warning on Wednesday to those due to attend, organisers Scum Tek said: "This party is going ahead, stay peaceful, stay calm. Patience and numbers is in our favour.

"Do not antagonise the police. We don't need to. At the end of the day we want to leave them remembering our good attitudes, we just came to dance, we are not their enemy."