A knife wielding youth injured in an assault was among those arrested in a dramatic police chase last night.

A group of youngsters scattered into surrounding streets when police officers on a routine patrol in Garratt Lane, Wandsworth, spotted what looked like a fight between two youths.

The alleged bust up in Thorndean Street was being watched by a group of teenagers, who fled when officers stopped at the scene, a Metropolitan Police spokesperson said.

Dozens of police officers in four patrol cars swooped on an alleyway near Weir Road, Wimbledon, one of whom was carrying a first aid kit, at around 6.30pm.

Subsequently four boys, aged 15, and 16 years-old, were arrested on suspicion of affray.

Some of the youths were apprehended in the Weir Road area after patrol cars blocked the road to passing traffic when they rushed to the scene.

A police spokesperson said that one of the youths, aged 16 years-old, was found in possession of a knife and arrested.

He was taken to a south London hospital for treatment to minor assault related injuries before being discharged and taken into custody.

Waiting police vans were on hand to escort the arrested youngsters to a south London police station where they remained over the weekend.

The CID on Wandsworth Borough is investigating the circumstances of the incident and enquiries continue.

Any witnesses or anyone with any information can call police on 101 or call Crimestoppers anonymously on 0800 555 111.