Manchester United are looking into allegations that fans were tear-gassed by French police at their Europa League tie in Lyon on Thursday night.
A number of supporters accused the police of acting in a heavy-handed way as they tried to go to the toilet after United's 2-2 draw at the Groupama Stadium. It's understood United are trying to gather the facts to establish a clearer picture of what happened.
Football Supporters Europe have hit out at the behaviour of the police, and executive director Ronan Evain said: 'It is completely unacceptable that the police would think it's okay to stop people from going to the toilets, and then the reaction to it is completely disproportionate.
'It is human nature that people will lose their temper if the police take away basic elements of basic human dignity like being allowed to go to the toilet.
'There, the police is responsible for creating this tension, for escalating and instead of taking the only logical decision in this situation, which is to permit people to go to the toilet, even if it's only small groups.
'That they're choosing to escalate this even further can’t be justified.'
United fans were kept behind late on inside the stadium - as away fans often are in Europe.
But the issues were alleged to have increased for United fans when one supporter shared a post-match video of a number of fans covering their noses, claiming that 'everyone' had been tear-gassed in the ground.
A video shared by @jaydeblanc on X received thousands of views and was taken inside the Parc Olympique Lyonnais away end.
United fans made up 3,000 of the 59,000-capacity stadium, and many were seen with their shirts over their faces after the full-time whistle.
'Everyone has been f***ing tear-gassed here,' a supporter could be seen saying in the video. 'What the f***ing hell is going on here?
'How the f***ing hell can they be using tear-gas at a football match?'
Another could be heard saying: 'That's what we get as United fans.'
As the camera panned round, more and more supporters could be seen covering their noses and mouths as the first fan added: 'Look at this, this is f***ing disgusting. People are being sick down here, f***ing hell.'
Coughing could also be heard in the background of the video, with other fans on social media also suggesting large sections of fans had been impacted.
As the video progressed, supporters could also be seen rubbing their eyes, covering their faces, and booing. It was said on social media that fans were warned of an hour's holdback with full access to facilities before police locked off the toilets and concourse and sprayed behind riot shields.
The alleged incident capped off a tough trip for United supporters, with every travelling fan mandated to collect a stadium wristband from the Eurexpo Conference Centre – around 10km away from Lyon's Groupama Stadium – between 5pm and kick-off.
Lyon's Metro system also failed before kick off, and transport bosses were forced to quickly put on replacement buses to get fans to the match on time.
French police and Manchester United were both contacted by Mail Sport for comment. United are looking into the matter, while one non-club-related fan page has asked for feedback for fans who attended the game.