Brighton fans suffered the affects of tear gas after it was used by police against AEK Athens supporters following their Europa League meeting on Thursday.
The Seagulls recorded a 1-0 victory over the Greek club at the Agia Sophia Stadium to reach the Europa League knockouts.
Joao Pedro scored the only goal of the match from the penalty spot while AEK Athens were reduced to 10 men as Mijat Gacinovic was shown a red card.
After the game, Sussex Police said a number of AEK ultras attacked the Brighton end and supporters of the Premier League club were held in the stadium.
Meanwhile, police used tear gas and flash bangs in order to make the home fans disperse.
‘Unfortunately after the game some of the Athens ultras stayed in the stadium and started to attack the Brighton fans,’ Sussex Police football officer Darren Balkham said.
‘Tear gas was deployed against the ultras and unfortunately that’s wafted through to the stadium.
‘We’ve made sure anyone with respiratory problems our youngsters have been put on the buses or been given paramedic care that they’ve needed.’
The violence marred what was a historic night for Brighton, described as a ‘massive evening’ for the club by captain Lewis Dunk.
‘It is a massive evening for the club and everyone involved, the players and the fans, a result we will always remember,’ Dunk told Uefa.com. ‘We had to show grit and determination. We didn’t play how we like to play, it’s not the football we usually play. But sometimes you win in another way.’