Wales boss Chris Coleman has pleaded with fans to avoid getting into trouble ahead of his side’s crunch clash with England in Lens on Thursday.
Coleman was speaking after police praised the travelling Wales fans for their behaviour following their 2-1 win over Slovakia.
The other Group B match between England and Russia was marred by fan violence inside and outside the stadium in Marseille.
Coleman, who blamed the crowd trouble on a “mindless minority”, said any aggression on show should be kept strictly on the pitch.
“It’s difficult to say to the Welsh public don’t come and sample the atmosphere,” he said. “It’s the Euros – they have been waiting for a major tournament for goodness knows how long. They deserve to enjoy this experience as much as anybody else.”
England and Russia have been threatened with disqualification by UEFA if there is any further violence from their fans.
There were around 24,000 Welsh fans present inside the stadium in Bordeaux to watch the Slovakia game and they were praised for their “great behaviour” after the game.
The Welsh F.A. has warned fans without tickets not to travel to Lens fearing there could be trouble as Russia will play Slovakia in nearby Lille a day earlier.