Racism appears to have blighted another English Premier League football game.
A video has emerged of a fan abusing Liverpool forward Mohamed Salah during the 1-1 draw with West Ham in London on Tuesday.
The Egyptian's Muslim faith is subjected to vitriol.
Officers are reviewing the footage.
The incident comesas the Football Association investigates claims Millwall supporters made racist remarks during their FA Cup victory over Everton last month.
In December, Chelsea suspended four people from Stamford Bridge pending an investigation into alleged abuse of Manchester City forward Raheem Sterling.
