Celtic fans have been advised not to use the metro system in Istanbul when they visit Turkey for next week's Europa League tie against Fenerbahce.
The warning was issued by the Foreign Office after a pipe bomb on an overpass near Istanbul's Bayrampasa metro station injured five people.
Fenerbahce host Celtic on 10 December, with the game kicking off at 18:00 GMT.
Travelling supporters have also been told not to display Celtic flags or scarves in public places.
Suburbs that house Fenerbahce supporters have been identified as areas Celtic fans should avoid, and supporters are advised not to travel alone to the Sukru Saracoglu Stadium.
The Bayrampasa district is on the European side of the city, while Fenerbahce's ground is in the Kadikoy district on the Asian side of the Bosphorus.
"The UK Foreign Office today issued special guidance for Celtic supporters travelling next week to Istanbul," said a spokesman for Uefa.
"In general, the summary is that there is no advice not to travel but the Celtic supporters are advised not to use the metro and to avoid public demonstrations."
Celtic cannot reach the next round of the Europa League but Fenerbahce are well placed to join Group A leaders Molde in the last 32, with Ajax two points behind the Turks.