Gianluigi Buffon and Marc Wilmots have condemned the violence that has marred the opening days of Euro 2016.
The dormant spectre of hooliganism re-emerged as the tournament kicked off in France this week, with Marseille particularly badly affected, as Russian and English fans clashed before their teams' 1-1 draw at Stade Velodrome on Saturday.
Asked for his thoughts on the incidents, Buffon said: "Deplorable, it tarnishes the competition and feeling of joy we should be experiencing.
"The build-up the tournament wasn't necessarily easy with regards to the general security of everyone," he added, referring to the threat of terrorism that overshadowed the potential for crowd trouble.
"So the fact that people aren't necessarily behaving like proper citizens and don't feel the desire to watch their team play and support their team, share with other fans everything that's great about sport - it's a real shame they're unable to do that."
Belgium coach Wilmots meanwhile called for UEFA not to punish players for the actions of supporters, as the European governing body flags potential sanctions against Russia, England and other countries whose fans misbehave.
"I think it's a very difficult debate," he said.
"It has nothing to do with the things that happens on the field.
"We've penalised some of the players [in the past] over the behaviour of so-called supporters.
"I saw something horrible, that was a man trying to run away [from the violence] with his son," he said, referring to footage from Marseille.
"That cannot happen in a stadium. Football is about celebration, that's why people go to the ground. We need to do everything in our power to try and rid football of this scourge. How do we do that? That's another question, I can't answer that question."
As for his country's match against Italy and the potential for issues at Stade de Lyon, he said: "I don't know what might happen or could happen.
"We asked our supporters to applaud the opposition national anthem. It's all about being well mannered and setting the right example."