A man was smashed over the head with a glass bottle after children were told off for splashing people with water in Catford, police say.
Officers were called at around 10.20pm on June 8 to Polecroft Lane in Catford where they found a man in his 20s suffering from serious head injuries.
Earlier that evening, at around 6pm, police believe a group of children were told off after they splashed people nearby during a water fight.
This led to a disagreement between two groups of men in Polecroft Lane later that day.
As a result, a man, 22, was hit over the head with a glass bottle and is now in hospital, in a stable condition.
Police want to trace three black men over the incident. The first is around 6ft tall, with a beard and short hair, wearing a black jacket with zip and collar.
Anyone with information should call Detective Sergeant Pete Campbell on 020 8284 8468 or Crimestoppers on 0800 555 111.