Armed officers will be deployed at Wembley Stadium for England's friendly match with France in the wake of the Paris terror attacks, the Metropolitan Police has said.
The international friendly is being played on Tuesday evening, just four days after the coordinated strikes across the French capital that saw 129 people murdered.
Fans have been told to expect an increased police presence at transport hubs and "in and around" the stadium, including armed officers.
Deputy assistant commander Peter Terry, from the Met's Specialist Crime and Operations Command, said: "We've reassessed what security we think we need for tomorrow night's occasion, which will of course be a fairly sombre occasion especially considering who we're playing."
Terry said no specific threat had been made against the match, but asked fans to be the police's "eyes and ears."
He urged supporters who noticed anything of concern to approach their nearest police officer, ring the counter-terrorism hotline or call 999.
Speaking outside Scotland Yard's headquarters, Terry said: "We've assessed what happened in France and we've changed what the appearance of the security will look like tomorrow.
"People travelling to and from the ground will see additional police officers at transport modes, they will see additional police officers on the walk up Olympic Way to the stadium, and in and around the stadium they will see armed officers, which is something they wouldn't normally see.
"I won't say that's the first time it's been deployed at a football match, but you will see officers out on foot carrying firearms tomorrow night."
There will be more police officers on horses and with dogs as part of the beefed up security operation, he added.
Police have asked fans to set off 30 to 40 minutes early as there will be extra searches at the stadium.
Terry said: "London and Paris are sister cities. They are extremely diverse and dynamic cities. They will not be cowed by the threat of terrorism.
"It's extremely important we show support to the people of Paris, people we have the greatest sympathy with at this moment in time, and show people we will go about our daily business."
The lyrics of the French national anthem, La Marseillaise, will be displayed on the big screens so that all fans can join in the singing.
Wembley's giant arch will shine in red, white and blue while the French flag and national slogan of 'Liberte, Egalite, Fraternite' will be shown displayed on LED screens on Wembley Way.
There will be a minute's silence before kick-off and both teams will wear black armbands to remember the victims of Friday's attacks.
Football Association chief executive Martin Glenn said: "7.55pm is when the game will really begin as we show our solidarity with France."