Ten teenagers have been arrested after a teenage girl was knocked unconscious in a serious assault in Mitcham.

Merton police are appealing for witnesses to the attack, which took place next to the Lidl car park in Raleigh Gardens at about 4.20pm on Friday, September 16. 

A spokesman for Merton police said: "There were about fifteen in the group, a mix of teenage boys and girls, who have assaulted a lone female, leaving her unconscious."

Anyone who was in the area or may have seen anything should contact Merton Police on 020 8649 3039, quoting reference 1411468/16. 

If you witnessed the incident and wish to remain anonymous, call Crimestoppers on 0800 555 111.