Wandsworth Police has reported finding a group of 20 males "beating up a 12 or 13-year-old boy" as part of a gang initiation.

Officers were called to Scholey House on the Winstanely Estate in Battersea yesterday (May 4) to reports of a 'gang initiation' happening in the block.

A Wandsworth Police spokesman said: "When officers arrived, they searched the stairwells of Scholey House and came across several males matching the description given of the group.

"On seeing police they made off and were chased on foot down the stairwells, where they were shortly detained several floors down.”

During the pursuit, which happened at around 7.10pm, officers found a bag that appeared in a stairwell "believed to have been discarded by the males as they fled".

Four male teenagers aged 16 to 19 were arrested on suspicion of possession of a firearm, and one was further arrested in custody for possession of cannabis.

The firearm has been confirmed as an imitation.

If you know anything which may help with police enquiries, please call 101 or Crimestoppers anonymously on 0800 555 111.