Tunisia has extended the state of emergency that has been in place since November 2015 for a further month.
The state of emergency was imposed following a suicide attack on a police bus and has been extended a number of times.
As part of its advice the travellers, the UK Foreign Office said the British government has been working with the Tunisian authorities to investigate the attack on British tourists in the holiday resort of Sousse in June 2015.
"The Tunisian government has improved protective security in major cities and tourist resorts," it said, "but terrorists are still very likely to try to carry out attacks in Tunisia, including against UK and Western interests.
"Security forces remain on a high state of alert in Tunis and other places. You should be vigilant at all times, including around religious sites and festivals."
