UEFA president Michel Platini admits he was "shocked" by the ugly scenes involving Serbia fans in Italy on Tuesday which caused the Euro 2012 qualifying match between the two countries to be abandoned.
Italy received a formal apology from the Serbian ambassador yesterday while UEFA launched an investigation into the crowd unrest which resulted in the game being halted after six minutes, with Italy coach Cesare Prandelli fearing a "tragedy" was unfolding.
The control and disciplinary arm of European football's governing body will not hear the case until October 28. UEFA described the incidents as "serious disorder".
Platini said: "On my return from the Netherlands I was shocked by the images of the Italy-Serbia match.
"I have too many bad memories associated with violence in football. I am awaiting the results of the investigation and the decisions of the disciplinary bodies and I remind everyone that UEFA has a zero-tolerance policy towards violence in stadia.
"The collaboration of the authorities is key to combating this scourge and I will request help from the highest level in those countries most affected."
When asked about the possible sanctions Serbia could face, Prandelli said: "We will wait with serenity."
Prandelli feared the worst when spectators in the Serbian section began throwing flares and other objects onto the pitch and into the areas where Italian supporters were seated at the Luigi Ferraris Stadium.
The same spectators tried to break through the barrier separating them from Italians, and there was little option for referee Craig Thomson other than to stop the match.
"After the initial delay we were ready to play," Prandelli said. "When I saw the 'Ultra' fans that were trying to break the wall that divided them from the Italian supporters, I was really frightened.
"I saw so many people with children running towards the exit. When it's like that, anything can happen. You needed very little to see an evening turn into tragedy."
Prandelli has experienced difficult situations before. The former midfielder was on the pitch for Juventus in the Heysel Stadium on May 29, 1985 when 39 fans died.
On Tuesday night, 17 Serbian supporters were arrested while 16 people were injured, including two policemen.
Northern Ireland will wait to hear UEFA's verdict as they plan their trip to Belgrade. The clash on March 25 is the next qualifying match for both teams.
Patrick Nelson, chief executive of the Irish Football Association, said: "We'll need to plan for that game in the near future. We plan all our trips carefully as all trips are different.
"We have a security officer as part of the team. We will work with him, UEFA and the other country, whichever country that may be."