Championship clubs Middlesbrough and AFC Bournemouth have condemned "vile" racist social media abuse sent to Yannick Bolasie and Arnaut Danjuma.
Both players posted details of racist online messages they had received, with Boro's on-loan Everton winger Bolasie calling abusers "keyboard warriors".
Danjuma's message followed an interview in which he expressed frustration at criticism of the taking a knee gesture.
Boro said the abuse was "unacceptable" and the Cherries said it "has to stop".
Bournemouth also reiterated their support for Netherlands forward Danjuma, 24, by adding: "Thank you for speaking up and we stand with you."
The offensive messages have been passed on to the authorities by the players and clubs.
"We will not tolerate abuse of any form," Boro's statement said. "The racial abuse directed to Yannick Bolasie on social media yesterday is vile and unacceptable, and demonstrates exactly why more has to be done to identify the perpetrators of such comments and to bring them to justice."
The Teessiders also highlighted their "zero tolerance" response to discrimination, stating any person found to be responsible for abuse would be subject to criminal proceedings and a ban from the stadium.
Everton, who loaned DR Congo international Bolasie, 31, to Championship side Boro in January, added: "Everton has a zero-tolerance approach to any kind of racism or discrimination. There is no room for racism in football or society.
"By working together, we can fight discrimination wherever it exists. Everybody has a part to play and social media abuse should never go unreported.
"We also urge social media platforms to strengthen measures to prevent this kind of behaviour. Through challenging it and reporting it, we can all play a part in changing it."
Manchester United's Marcus Rashford and Anthony Martial, Arsenal's Willian and Chelsea's Reece James are among a host of players to have been subjected to online abuse recently, prompting English soccer bodies to put pressure on social media companies to tackle the problem.
