Dozens of Manchester United fans descended on the Carrington training ground to protest against the club's owners, the Glazer family.
Placards reading "Glazers out" and "Shame on wearing a United shirt" were held up outside the gates of the complex, with United officials stepping up security and notifying the police.
The fans of the English club have warned that they will continue the protests in the stadium in the Premier League match against Norwich on Saturday.
A statement from United read: "There was a small and peaceful protest outside the Carrington training ground today. We respect the views of the fans and remain committed to strengthening our engagement with them," the statement read.
The fan protests have come as a result of the club's poor results this season.
