More British police are to be sent to France ahead of England's clash with Wales, Home Secretary Theresa May has confirmed as she warned football fans to "stay out of trouble".
The note of caution came as Uefa handed Russia a suspended disqualification from the European championship for crowd disturbances in Marseille, meaning they could be kicked out if similar incidents occur.
The Home Secretary today told Cabinet of extra British public order police and transport police being dispatched to the tournament, and confirmed the news in a statement to the House of Commons.
She added: "I would conclude by echoing the England captain and manager, who have urged fans to stay out of trouble.
"As the Uefa decision in relation to the Russian team shows, the penalties for individuals and the teams they support could be severe if there is more violence in the days ahead."
Uefa on Sunday warned that both Russia and England could be expelled from the tournament if the confrontations, which have already lasted three days, continue.
Hundreds of outraged England fans called for Russia to be stripped of its hosting of the 2018 World Cup after England supporters were attacked in the stands after Saturday’s 1-1 draw.
England fans were seen fleeing the stands shortly after the final whistle was blown as balaclava-clad thugs punched through a line of stewards before attacking bystanders.
Earlier, the Prime Minister's spokeswoman said that today's Cabinet meeting discussed the violence at the Russia-England match.
Culture Secretary John Whittingdale said that he had contacted the Russian sports minister and they had agreed a joint approach to warning their fans to behave.
When asked about a Russian MP's support for his country's fans' conduct, No10 said: "Clearly we condemned the violent behaviour at the weekend and we would expect others to do so too.
"The Russian sports minister was very clear with the Culture Secretary that they want a peaceful and safe tournament and will work with us and the French authorities."