'West Bromwich Albion fans' graffiti Wolves' training ground
Police are hunting two men who filmed themselves spraying the Wolverhampton Wanderers training ground with rival graffiti.
The men, believed to be West Bromwich Albion fans, posted a video online showing them writing "W.B.A Boing Boing" on the wall in Compton.
West Midlands Police said it was investigating criminal damage after receiving a formal complaint.
The force has urged the men to turn themselves in.
Supporters of West Brom are known to chant 'boing boing' while jumping up and down.
The graffiti was sprayed on the wall at the Jack Hayward training ground between Friday morning and Sunday night, police said.
"We are aware of a video that has been circulated via Facebook which allegedly shows a man spraying the wall with paint," a spokesman said.
"I would urge the person who filmed this and the man in the video to come forward and speak to us before we come knocking on their door."