A man is receiving hospital treatment for serious head and facial injuries after being attacked in a West Lothian nightclub.
The incident happened at the Envi nightclub in Bathgate's Hopetoun Street at about 02:40 on Easter Sunday.
The 31-year-old victim sustained the injuries when he was hit in the face while on the dance floor.
Police said he was taken to St John's Hospital in Livingston, where he remains.
They appealed for help in tracing his attacker.
Det Con Ross Collett said: "Neither the victim, nor those he was with, saw who struck him and we are therefore keen to speak to any other patrons who were in the club and saw what happened.
"Likewise if you have any other information that can assist with our inquiry then please contact police immediately."