The biggest soccer crowd in England since players started taking a knee saw the anti-racism gesture booed by some fans before the FA Cup final between Chelsea and Leicester on Saturday.
The jeering was heard over some applause as more than 20,000 supporters were allowed inside Wembley Stadium after producing negative coronavirus test results.
It is the largest gathering of any form in Britain since the start of the pandemic in March 2020.
Players started taking a knee when the Premier League resumed from its 100-day shutdown in June 2020 as part of calls to eradicate racial injustice in society following the police killing of George Floyd in Minneapolis.