Police have launched an investigation into an attack on the home of Manchester United executive vice-chairman Ed Woodward as fans' frustrations mount over the plight of the 20-times English champions.
Videos shared on social media on Tuesday show hooded people throwing flares over a gate to a property, while red paint was sprayed on a gatepost.
A statement from Cheshire Police said officers were notified of an incident of criminal damage at around 10:45 pm (2245 GMT) on Tuesday.
"Thankfully no one was harmed and officers will liaise with security officials over the coming days to establish the full circumstances surrounding this incident and identify those involved," the statement said.
Woodward, who is married with two young children, is reported to have been away from his home at the time of the attack.
United said those responsible would be banned for life from the club.
"We know that the football world will unite behind us as we work with the police to identify the perpetrators of this unwarranted attack," the club said.
"Anybody found guilty of a criminal offence, or found to be trespassing on this property, will be banned for life by the club and may face prosecution.
"Fans expressing opinion is one thing, criminal damage and intent to endanger life is another. There is simply no excuse for this."