Four men broke into Manchester United's Old Trafford stadium ahead of Michael Carrick's testimonial last week, according to the BBC.
The "urban climbers" breached security by getting onto the stadium roof and pitch just hours before last Sunday's game and less than two weeks after the Manchester terror attack, which left 22 people dead.
The men were chased by security staff and managed to avoid capture, while no arrests were made, the police said. The group targeted Old Trafford shortly after getting on the roof of a hotel in the centre of Manchester.
A United spokesman said: "Their stupid and irresponsible actions, especially at such a sensitive time, put last Sunday's game at risk and occupied both club staff and, more importantly, police officers in hours of work to make sure that the stadium was safe to stage the match.