A 23-year-old man has died after being stabbed on the dancefloor of a nightclub in Birmingham on St Stephen's Day.
Police were called to the Crane venue in Adderley Street, Digbeth, just before 11.45pm to reports that the victim had been injured.
The man had been on a night out with friends when he was approached by a group of people, according to West Midlands Police.
Despite efforts to save him, he was pronounced dead around half an hour after officers were called, the force said.
Police said hundreds of people were in attendance at the nightclub at the time and urged any witnesses to come forward.
Detective Inspector Michelle Thurgood, leading the investigation, said: “This was a young man enjoying himself with friends on a Boxing Day night out and our thoughts are with his friends and family today.
“We know there were hundreds of people in the nightclub at the time. While we’ve spoken to a number of them already, we still need to hear from anyone who was there and who witnessed or even filmed what happened.
“We believe that the victim was approached by a group of people, and was then stabbed, so we’re working hard to identify all of those involved.”
The victim’s family has been told and will be supported by specialist officers, the force added.
The scene remains closed while evidence is gathered and neighbourhood officers will be patrolling the area over the coming days to offer reassurance, police said.