The UK Foreign Office has advised British citizens not to travel to Sri Lanka unless their journey is essential.
The change in advice comes after the deadly Easter Sunday bombings, which killed 359 people and injured 500.
In the immediate aftermath of the bombings, the Foreign Office updated its guidance, urging British citizens to avoid large gatherings.
But on Thursday it went further, warning about the potential for further attacks.
It said: “The Foreign and Commonwealth Office advise against all but essential travel to Sri Lanka, due to the current evolving security situation following attacks on 21 April 2019. Terrorists are very likely to try to carry out attacks in Sri Lanka.”