Four people are being questioned by police after a man suffered serious head injuries in an assault in Surrey.
He was punched by a youth who was part of a group of teenagers in an alleyway behind Fairview Road, in Ash, at just after 2000 BST on Wednesday.
Police said it was linked to an earlier incident in Ash Skate Park in which a dog walker had a stick and stones thrown at her and her pet.
A 14 year old, a 19 year old and two 16 year olds are in police custody.
The 46-year-old victim and two other men, aged in their late teens, had been looking for the group responsible for the altercation with the dog walker.
The woman suffered a cut to her thigh.