Police Scotland has also said it was investigating after Rangers players Emmanuel Fernandez and Djeidi Gassama shared screenshots of racist abuse aimed at them on their social media accounts after Sunday’s 2-2 draw at Livingston.
Kick It Out said reports of online abuse were at record levels, increasing by a third compared with the same point last season.
Mike Ankers, UKFPU deputy director, told BBC Radio 5 Live the police unit has had an increase of about 115% in the number of reports.
“I don’t know really why, but I repeat – we don’t want to accept that,” added Le Bris.
“We have to have a clear position and I think it’s the case here at Sunderland, we want to defend values and when someone, a group of people, wants to threaten those values it’s important to react.”
Edwards added: “There have been a number of these instances, and very high-profile over this last week, which is really sad.
“They say, ‘I’m OK, I have had it before’. I think that is what is difficult. That is tough to hear.”
Edwards said Arokodare had trained this week and, despite being affected by the abuse, was “all right to play” in his side’s home game against Aston Villa on Friday, which kicks off at 20:00 GMT.
However, Le Bris said Mundle “might be sidelined for a few weeks or months” with an injury and would miss Sunderland’s game at Bournemouth on Saturday.
Responding to the Fofana and Mejbri abuse, a spokesperson for Meta, which owns platforms including Instagram, told BBC Sport: “No-one should be subjected to racist abuse, and we remove this content when we find it.
“No one thing will stop racist behaviour overnight, but we’ll continue working to protect our community from abuse and co-operate with police investigations.”
