Terror threat advice for Britons travelling to popular destinations

UK citizens travelling abroad are told to be on their guard in the face of the continuing danger posed by extremists.

Image Caption: France has been on high alert after a series of terror attacks

British tourists in Turkey have been urged to follow the advice of the authorities and remain vigilant after the New Year's Day nightclub massacre in Istanbul.

The Foreign and Commonwealth Office (FCO) already advise against all but essential travel to the southeast of the country along its border with conflict-torn Syria and Iraq.

Image Caption: A gunman killed at least 39 people at a New Year party in Istanbul

Despite recent attacks, the FCO states it is "generally safe" to travel to the rest of Turkey but advises "additional safety precautions", including being "alert to your surroundings".

It has been warned there is a "high threat" from terrorism in the country and that Kurdish groups, Islamic State and far left organisations "continue to plan and carry out attacks".
"Further attacks are likely and could be indiscriminate," according to the FCO website.
It tells Britons: "You should be vigilant, follow the advice of local security authorities, monitor media reports and keep up to date with this travel advice."
Here is what the Foreign Office has to say about other top destinations for UK visitors.
:: France - high threat from terrorism
Due to ongoing threats to France by Islamist terrorist groups and recent French military action against Islamic State "the French government has warned the public to be especially vigilant and has reinforced its security measures".

Image Caption: The lorry attack on a Berlin Christmas market left 12 dead

:: Germany - high threat from terrorism
In the wake of the lorry attack on a Berlin Christmas market that killed 12 people: "The German government has announced that increased security has been put in place as a precaution at public buildings, major events, transport hubs and large public gatherings."
:: Greece - general threat from terrorism 'and acts of political violence'
The FCO states: "Attacks could be indiscriminate, including in places frequented by foreigners.
"High profile British interests in Greece should be vigilant and regularly review their security measures."

Image Caption: UK visitors to Italy are advised to be vigilant

:: Italy and the Netherlands - general threat from terrorism
Travellers are warned of the likelihood of an increased security presence at major events that may attract large crowds.
People are advised to "remain vigilant and follow the advice of local authorities".
:: Portugal - underlying threat from terrorism
Attacks, although unlikely, could be indiscriminate, including in places frequented by expatriates and foreign travellers.
:: Spain - general threat from terrorism
Attacks could be indiscriminate, including in places visited by foreigners.
While the Spanish authorities took measures to protect visitors, people "should be vigilant and follow the instructions of the local authorities".

Image Caption: British officials say attacks in the US could be indiscriminate, such as a blast in Manhattan in September

:: US - general threat from terrorism
The FCO states: "Attacks could be indiscriminate, including in places visited by foreigners. You should monitor media reports and remain vigilant at all times."
It says individuals could be "inspired to target public events or places", as highlighted by attacks in New York, Orlando and San Bernardino.
"Attacks could take place with little or no notice," it adds.