Former Chelsea star Salah is a Muslim, and Kick it Out swiftly declared the chant ‘a disgrace’.
The anti-discrimination organisation said in a statement: “It’s not on the terraces but it is still a disgrace.
“We do not want fans like that anywhere near our game. We will be liaising with Chelsea Football Club to ensure those involved are identified and punished swiftly and effectively.”
The video went viral on social media on Thursday afternoon before the match in Prague against Slavia in the Europa League – and appeared to show a group of fans in a bar singing the derogatory chant.
Chelsea’s Europa League campaign has been dogged by the misconduct of their travelling supporters.
The club were investigated earlier this year after alleged racist incidents during their Europa League clash against MOL Vidi in Budapest.
They were also shown holding up a flag with a Nazi symbol.
The charges were related to antisemitic chanting against Tottenham fans – but were eventually dropped.
On that occasion, the club publicly condemned their supporters and urged fans to ‘summon brainpower’.
Chelsea fans were again at the centre of trouble at the end of last year after alleged racist abuse of Manchester City star Raheem Sterling at Stamford Bridge.
Chelsea declined to comment “on the basis that it has not been established that these are Chelsea fans”.
The club later confirmed that three of the six fans were identified and turned away from the stadium.