A man was knocked unconscious after being struck on the head with a cricket bat, leaving him with a blood clot in his brain.

The attack, which happened in Southall Park, Ealing, west London, followed a verbal altercation between the victim and a group of men playing cricket, the Metropolitan Police said.

The 21-year-old man was returning home, having attended Vaisaki (Sikh New Year) celebrations on Southall Broadway on April 11, when he passed the men playing cricket.

As he passed, he was struck to the back of his head with a bat, leaving him unconscious for about 10 to 15 seconds.

Officers were alerted by members of the public and he was taken to a hospital in west London where he was treated for a blood clot in the brain. He has since been discharged.

No arrests were made and police are appealing for witnesses to come forward.

A police spokesman said the attacker is thought to be between 18 and 25, of Asian or Arabic appearance, with short black hair and a beard.

Detective Constable Jaspal Bains, said: "The area was very busy that day due to the Vaisaki celebrations taking place and I am appealing to anyone that was in the area that saw this assault to contact me."

Anyone with information can call Ealing CID on 101 or Crimestoppers anonymously on 0800 555 111.