In response to the racist abuse, anti-discrimination group Kick It Out said it had been an “appalling weekend” but “the sad fact is, we know it happens regularly”.
“As the law enforcement lead for online abuse connected to football, the UKFPU will be working closely with all the football clubs and their players to help identify the people responsible,” said a police statement.
“Over recent months the UKFPU have seen a number of successful prosecutions for online racial abuse, which have resulted in significant football banning orders.
“However, we recognise that there is always more to do, and we will continue to work closely with Ofcom, English football authorities, and social media platforms to tackle the issue.”
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.”
Last November, a BBC investigation found more than 2,000 extremely abusive social media posts – including death and rape threats – were sent about managers and players in the Premier League and Women’s Super League in a single weekend.
The season-opening Premier League game between Liverpool and Bournemouth in August was stopped after then-Cherries forward Antoine Semenyo reported being racially abused by someone in the Anfield crowd.
A Liverpool man has denied the abuse and his trial is scheduled to take place in April.
In January, Newcastle United said they had contacted police after midfielder Joe Willock was the subject of “disgusting” racial abuse and “deeply disturbing threats” on social media.
Tottenham forward Mathys Tel was also the subject of racist abuse on social media after being one of two Spurs players to miss in their Super Cup penalty shootout defeat by Paris St-Germain in August.
England defender Jess Carter was another target of racist abuse during Euro 2025 in July.
And England internationals Marcus Rashford, Jadon Sancho and Bukayo Saka were all subjected to racism in the aftermath of the Euro 2020 final, which the Three Lions lost to Italy in a penalty shootout.