Police have asked for help in finding a man who was caught on camera hitting golf balls at a railway station late at night.
The man was filmed at Sunderland's South Hylton Metro station, placing balls on the platform and then smashing them up the track.
He then caught a Metro to Pallion and, when he got off, he hit some more shots before urinating on a cycle rack.
The golfer was carrying a bag of clubs and was with another man, two women and young children, at 11.20pm on Saturday May 25, officers said.
British Transport Police, who released still images of the man, said no-one was injured.
Pc Mark Bradwell said: "While it may seem that the man was simply having a bit of fun, in reality this kind of behaviour is very dangerous.
"Fortunately, none of the golf balls hit any trains or passengers on this occasion, but the consequences could have been far worse had that been the case.
"The railway is a dangerous environment with moving trains and electric currents. It is certainly not a playground."
A Metro spokesman said: "Behaviour of this nature on the Metro system is totally unacceptable and extremely rare."
Anyone who recognises the man should ring British Transport Police on Freefone 0800 40 50 40, text 61016 quoting reference B2/NEA of 13/06/2013, or call Crimestoppers on 0800 555 111.