The Foreign Office has warned UK fans travelling to Paris for the Euro 2016 football tournament to remain "vigilant at all times" as busy areas could be "potential targets for terrorist attacks".
The updated advice from the Foreign and Commonwealth Office has highlighted stadiums, fan zones and other venues broadcasting the tournament as potential targets for atrocities.
British counter-terrorism officers are playing "a key part" in planning against attacks which may target the tournament and and a UK intelligence team has travelled to Paris to work with their French counterparts to assess possible threats.
It comes after Ukranian police said they had arrested a French terror suspect - who is believed to hold far-right views - who was gathering heavy weapons and explosives to target Muslim and Jewish places of worship as well as administrative buildings and infrastructure such as bridges and railways during the tournament.
Police say the unamed man was arrested in late May on the border with Poland carrying 125kg of TNT which he had acquired in the restive eastern Ukranian province of Donetsk.
Last week the US State department issued a travel alert warning US citizens to "exercise vigilance" and "avoid crowded places" when travelling in Europe during the summer but did not refer to the Euro 2016 tournament specifically.
France's national stadium, the Stade de France, was one of the targest of the Isis terror attacks on Paris in November last year.
Three suicide bombers detonated their explosives outside two of the entrances to the stadium and at a fast-food outlet nearby when they could not get inside.
