Hundreds of Manchester United fans, protesting against the club's US owners, invaded the pitch at Old Trafford stadium on Sunday ahead of the Premier League game against Liverpool, according to multiple British media outlets.

A number of Man United supporters are unhappy over the club's failed attempt to join the European Super League last month. The Glazer family, which also owns the NFL's Tampa Bay Buccaneers, runs Manchester United.

"Hundreds of fans have been on the pitch and many are now exiting through gates across a road that normally allows the team buses through," wrote BBC reporter Simon Stone, who is at Old Trafford.

Manchester United and Greater Manchester Police did not immediately respond to CNN's request for comment.

Initially the Premier League said it expected the game to kick off at 4.30 p.m. local time, but the start was then pushed back, according to the BBC and Sky Sports.

Manchester United -- and Liverpool -- were two of the 12 clubs that last month announced their intention to break away from the current UEFA competition format and create their very own European Super League, before the project quickly unraveled.

"We are disgusted, embarrassed and angry at the owner's actions in relation to the planning, formation and announcement of the European Super League," said the Manchester United Supporters Trust at an emergency fans forum meeting on Friday.

"Once again this clearly demonstrates that the club's owners are only interested in maximising their own profits and do not care about or respect the views of Manchester United fans."