Operation Optic will target six boroughs known for alcohol violence over the next few weeks.

Police will not say which boroughs will be targeted but they will be looking for under-age drinkers.

Metropolitan Police Commissioner Sir John Stevens said police will also concentrate on pubs and clubs selling alcohol to intoxicated people.

"People should be under no illusions we will use the weight of licensing legislation to get places shut down if trouble continues," he said.

"What we are saying is if you want to go enjoy yourself, go and do so, but don't start coming out into the street spitting and trying to punch people, taking over the street and frightening the public."