A man is in a life-threatening condition in hospital after being headbutted outside a nightclub in Manchester.
He was subjected to a "random" attack outside the Void venue in the early hours of Sunday, Greater Manchester Police said.
He fell to the floor at the scene in Richmond Street but got up again, before falling unconscious and going into cardiac arrest. He is in a "life-threatening" condition in hospital, police added.
The street runs parallel to the city's famous Canal Street, a hub for the LGBT community.
Detective Sergeant Phillip Marsh said: "This horrific and random act of violence has left a man in a critical condition in hospital.
"The motive for the attack is not clear but we do believe it was a completely unprovoked attack on an innocent man."
The assault happened at around 5.50am. The attacker is described as an Asian man in his late 30s to early 40s, wearing blue jeans, a black t-shirt and brown boots.