UEFA have opened disciplinary proceedings against Chelsea over the conduct of their supporters during Thursday's 2-1 win over Malmo in the Europa League round of 32.
The charges specify the throwing of objects in the stands and a field invasion by several supporters on the final whistle -- one of whom caused security concerns by grabbing winger Eden Hazard and refusing to let go until the Belgian gave him his match shirt.
Malmo have also been charged with the throwing of objects as well as the setting off of fireworks during the match, which Chelsea won courtesy of goals in each half from Ross Barkley and Olivier Giroud.
Chelsea are already facing a partial closure of Stamford Bridge for a future European match as a result of separate UEFA action on a charge of racist behaviour, with the punishment to be determined at a meeting of UEFA's Control, Ethics and Disciplinary Body on Feb. 28.
In a statement, UEFA said: "Disciplinary proceedings have been opened following the UEFA Europa League Round of 32 match between Malmö FF and Chelsea FC (1-2), played on 14 February in Sweden.
"These cases will be dealt with by the UEFA Control, Ethics and Disciplinary Body on 28 March."
Chelsea have little time to dwell on future punishments from European football's governing body as they attempt to navigate a run of matches that could define their season.
Manchester United visit Stamford Bridge in the FA Cup fifth round on Monday, with the Carabao Cup final against Manchester City and a Premier League clash with Tottenham to follow in what remains of February.
"We know it's a crucial moment," Chelsea assistant Gianfranco Zola said in a news conference. "We have some very important matches. The next three are United in the fifth round, then the Carabao Cup final and Tottenham in the league, where we're playing for the Champions League spot.
"It's an important moment, very challenging. The key will be to face each task only thinking about that particular task. The first will be United, and we come into this game after a good performance in the Europa League. That's the most important thing. Then we'll think about City and Tottenham."
Chelsea have no new injury concerns ahead of the United game, with Ruben Loftus-Cheek potentially available again after missing the trip to Sweden with back pain and several other key names rested from Maurizio Sarri's starting XI in the Malmo win.
Callum Hudson-Odoi was given just six minutes off the substitutes' bench against Malmo just over a fortnight after failing in his attempt to force a January move to Bayern Munich, but Zola bristled at the suggestion that Sarri could be doing more to make the 18-year-old feel involved and valued.
"I disagree on that," the Italian said. "He's always on the edge of the team. As soon as there is an opportunity, he plays. Sometimes from the beginning. Sometimes he comes on. The manager is giving him plenty of reasons to feel involved and wanted.
"I want to stress this out: there aren't many 18-year-olds in Europe playing as many games as he is. There might be one or two. He's playing. And, on top of that, he's a player we appreciate and we believe is growing up. He has a bright future in this club.
"Maurizio likes... the whole coaching group like him. Please, you need to understand that he's surrounded by top players. You have to work hard to be better than them, and that's what we want. We want him to play but also keep improving. He can still do better than he's doing."