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Spectators at English football club Millwall marked the return to stadiums by booing as players took a knee before Saturday’s game against Derby County.

Up to 2,000 supporters are permitted in football stadiums in some areas of England as part of new government measures introduced this week, the first time fans have been allowed to attend games since the coronavirus outbreak.

In footage on social media, fans at The Den, Millwall’s home ground in southeast London, can be heard booing as players from both sides take a knee before kick-off.

Across English football, players have been taking a knee in support of the Black Lives Matter movement and to protest against racism and discrimination following the death of George Floyd earlier this year.

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Millwall players kneel before their side's game against Derby County.

All Premier League clubs have continued to kneel before games this season, while some teams in the English Football League, the second, third and fourth tiers of English football, stopped at the start of this season.

Millwall issued a statement on Sunday saying the club was “dismayed and saddened” by events at the game.

“The club has worked tirelessly in recent months to prepare for the return of supporters and what should have been a positive and exciting occasion was completely overshadowed, much to the immense disappointment and upset of those who have contributed to those efforts,” it said.

It also said that the club, its academy and community trust staff would meet with representatives from anti-racism body Kick It Out and other organizations to ensure the events from the game become “a catalyst for more rapid solutions which have an impact both in the short and long-term.”

The statement added: “There is much work to be done and at Millwall everyone is committed to doing all that is possible, both individually and collectively, to be a force for good and to ensure that the club remains at the forefront of football’s anti-discrimination efforts.”

On Friday, Millwall issued a statement reaffirming the club’s stance on players taking a knee.

“As a squad we are fully supportive of the entire football family’s efforts in ridding the sport, and society generally, of all forms of discrimination,” the statement said. “It is our duty as players to reinforce the positive messaging and action of clubs, community trusts, charities and governing bodies, and we do so with great pride and knowledge that so much good work is being done up and down the country.”

Derby celebrates scoring against Millwall.

Saturday’s game ended 1-0 in favor of Derby, the Rams’ second league victory of the season.

Sanjay Bhandari, chairman of Kick It Out, said the organization is “saddened” by the booing of players taking a knee at Millwall.

“What this demonstrates is that players are right to continue standing up to discrimination, whether that is through taking the knee or speaking out,” he said. “The fight for racial equality continues and we will continue to work closely with clubs across the country to tackle discrimination in all its forms.”

In a statement, the English Football Association said it “supports all players and staff that wish to take a stand against discrimination in a respectful manner, which includes taking of the knee, and strongly condemns the behaviors of any spectators that actively voice their opposition to such activities.”

CNN has contacted Millwall for comment but did not immediately receive a response.