Uefa has officially launched its investigation into the crush scare involving Manchester United fans at the Champions League tie against Lille.
United fans were involved in a security scare in Lille
United fans appeared to be pushed against a 10-foot high fence and at least two people were lifted to safety.
Riot police then fired tear gas and swung truncheons at those who were trying to climb over the fence.
And Uefa are investigating "possible violations of binding Uefa safety and security instructions by the hosts".
A statement from Uefa added that it will also look into the "alleged improper conduct of both sets of supporters".
The control and disciplinary body will meet on 22 March to discuss the incidents, effectively ruling out the expulsion of the French side from the tournament in the way Feyenoord were kicked out of the Uefa Cup this season for crowd disturbances.
The Old Trafford club are appealing for eye-witness reports to the incidents at Lens' Stade Felix-Bollaert.
I've policed games for 18 years and I've never seen anything like it - we were treated barbarically
British police officer in Lens as a Man Utd fan
Fans who were at the game have already criticised the actions of the French police.
One supporter - himself a serving police officer who cannot be named - told the BBC: "I was appalled by our treatment by the French police from the moment that we arrived.
"I couldn't believe the state of the ground - it was like returning to the era before all-seater stadiums. We were fenced in like cattle only treated worse.
"In addition to being treated barbarically by the police, we were constantly targeted by the Lille fans directly above us in an upper tier.
"Throughout the match, coins and other missiles rained down and yet the police did nothing. There has to be a full Uefa investigation."
Another fan, 27-year-old Mark Harrison, from Lymm, Cheshire, said: "I think people were worried it might be like Hillsborough, so they started climbing the fence and trying to get out the stand.
606 DEBATE: Were you at the game in Lens?
"The police reaction was well over the top, they started spraying us with pepper spray, my eyes were streaming and I couldn't catch my breath."
United goalkeeper Edwin van der Sar suffered double vision as a result of the tear gas fired into the stand.
Television reports suggested the gates at the back of the stand had been opened by police to allow United supporters with tickets for the home section of the stadium to sit with their own fans.
I think one's got to be asking Uefa are they now going to be taking action
Sports Minister Richard Caborn
United had expressed concerns about the basic facilities at the ground before the match, and queried the decision to move the game to the compact 42,000 stadium in northern France rather than a larger, more modern venue like the Stade de France.
Manchester United secretary Ken Ramsden revealed the club would meet with Uefa and Football Association officials to discuss the incident.
A Manchester United club official, at the match, said he had not been made aware of any injuries to fans.
Meanwhile, sports minister Richard Caborn has pleaded with Uefa to ensure grounds used for the Champions League meet minimum safety requirements.
"I think some of the grounds are not coming up to what even Uefa are saying are the minimum standards," he said.