Wednesday 8 June 2016 00:28, UK
Fans travelling to Euro 2016 in France have been warned by the Foreign Office to be on their guard against terrorists.
In a statement, it said that "stadiums, fan zones, venues broadcasting the tournament and transport hubs and links represent potential targets for terrorists".
And it also warns supporters of visiting teams to be "vigilant at all times, especially in areas hosting Euro 2016 events, and follow the advice of local French authorities".
It comes after officials in Ukraine revealed they had arrested a Frenchman who was plotting a series of strikes in his homeland, although the Foreign Office says this is not the reason for it issuing fresh guidance.
Commander Dean Haydon, the head of Scotland Yard's anti-terror squad, said it is working closely with the French authorities and other police and intelligence services across the world to make the championships as safe as possible.
He said: "Certainly we have seen propaganda, Islamic State (IS) and potential talk of plots against the Euros, but we're working with all those various different agencies to police and make (them) a safe event and a safe games.
"We're a key part of the planning. Although the ultimate policing of the event and the planning is for the French, we are all involved in properly trying to understand the threat, if there is one."
A police operation targeting 29 UK ports in the run-up to the tournament began on Monday, with staff keeping special watch for football hooligans trying to sneak out of the country.
Currently 1,841 England fans and 86 Wales supporters are subject to banning orders that stop them travelling to the Euros.
Matches at the championships will be played at a number of stadia across France and there are a string of fan zones for thousands of supporters. Fan zones will also be set up in London, which Mr Haydon said will be policed "normally".
"The threat level in the UK remains at severe, so an attack is highly likely - that has not changed," he said.
"If we see increased intelligence coming out of France or anywhere in the world that suggests there's going to be an attack here then of course, through Cobra (emergency committee) and Government, we will review that threat level accordingly."
On Monday Prime Minister David Cameron chaired a meeting to review preparations for the tournament.
A Foreign Office spokesman said: "We have updated the travel advice to provide further information for fans on the risk of terrorism in France as they start to travel for Euro 2016.
"This is consistent with the advice we have already issued for France and is not in response to a new or specific threat or yesterday's (Monday's) arrest."
A Downing Street spokeswoman said the French authorities "have got an extensive security operation in place", with 77,000 police and gendarmes, 10,000 military personnel and a similar amount of security guards.
She added: "We are providing additional counter-terrorism and public order support to the French. That includes, for example, the deployment of additional police on trains into France and more UK Border Force outbound checks."
