By Lucien Libert

LENS, France (Reuters) - Thousands of England and Wales fans gathered in the French town of Lens for their team's Euro 2016 soccer showdown on Thursday, with police braced to prevent more of the violence that has brought England and Russia the risk of expulsion from the tournament.

French riot police charged and used tear gas to disperse rowdy English soccer fans in the nearby northern city of Lille on Wednesday night. Police said about 50 people were hurt, 16 of them hospitalized.

UEFA said on Thursday it regretted the violence but it stopped short of action to punish the fans or teams.

The governing body of European soccer said it was planning no Executive Committee meeting in the wake of the overnight violence on the streets of Lille.

The decision effectively means England are not under any immediate threat of disqualification over their fans' behavior as any decision to expel England for crowd disturbances outside the stadium would need to be taken by the executive committee.

Thursday afternoon's Group B match between England and Wales in the Euro 2016 group has been dubbed "The Battle of Britain".

Lens Prefect Fabienne Bucchio told reporters the town was quiet so far. Only nine people were detained by police overnight, she said, all in connection with minor incidents of drunkenness. Eight of them were French.

"Everything is in place and working. We will do all we can so that it remains a festival," she said.

After violence in the Mediterranean port of Marseille before and after England's 1-1 draw with Russia on Saturday, UEFA warned England that a repetition of fans' violent behavior could see the team expelled.

UEFA also told Russia that it would be disqualified if there was a repeat of their fans' violent behavior, which included attacks on England supporters in the stadium as the match ended.

Throughout Wednesday, 36 people were arrested for various offences as Russia lost to Slovakia in Lille and England prepared to play Wales, police said.

On Thursday morning, police checked fans boarding trains from Lille to Lens to ensure none were traveling with alcohol, leading to long queues. A heavy police team carried out similar checks in pouring rain on arrival 45 minutes later in Lens.

"We’re just hoping it's a carnival atmosphere," said one Welsh fan as he left the train.

A set of Birmingham City supporters backing England took an early morning train from Brussels, where they had stayed overnight to keep away from any potential violence in Lille.

They were already on their second cans of lager as the train pulled away.

Fans poured into the bars near the station, some staked out more by English, some more by Welsh fans, although early signs were of the two sets of supporters happily mingling.

"It was a strange atmosphere last night, drinking in a bar in the center of Lille, with a wall of riot police in front of you. We’ll be fine with the Welsh," said a Coventry City fan eating a sandwich on the route towards the Stadium Bollaert-Delelis.

RESPECT

Martin Glenn, the chief executive of England's Football Association, urged England fans to show "consideration and respect" as French police were already pre-occupied with preventing any militant attacks.

France has suffered several attacks by Islamist militants in the past two years, including a shooting rampage in Paris in November that killed 130 people. Two French police officials were killed on Monday by a man claiming allegiance to Islamic State.

"The French are trying to deal with a real security threat," Glenn told the BBC. "Behave responsibly, come and enjoy the game, but just have a think about the wider position."

Separately, police in Lyon in southeast France said two fans suffered stab wounds in a fan zone there on Wednesday.

Lyon police said one of those wounded, a Frenchman, had told them one of his attackers wore an Albania soccer shirt. France beat Albania 2-0 in another of Wednesday's games.

Interior Ministry figures released on Thursday showed 196 people had been detained by police and eight of their number handed firm jail terms so far in the tournament, which lasts until July 10. Twenty-four people have been expelled from the country

Marseille police said a further 20 Russian fans were to be expelled from France, including Alexander Shprygin, the head of a Russian supporters group.

(Additional reporting by gerard Bon, Chine Labbe, Julien Pretot and Catherine Lagrange,; Writing by Andrew Callus and Angus MacSwan; Editing by Jon Boyle)