Thousands of British tourists have begun to arrive home from Tunisia after the Foreign & Commonwealth Office (FCO) issued a warning that another terror attack is “highly likely”.

The alert comes after 38 tourists, including 30 Britons, were killed in an Islamic State-linked terror attack on a beach in Sousse on 26 June.

More than 3,000 British tourists, including around 2,500 package holidaymakers and 500 independent travellers, are believed to be in Tunisia.

The Association of British Travel Agents (ABTA) advised all British holidaymakers in Tunisia to contact their travel company to confirm arrangements for returning home and warned that the change in FCO travel advice would likely invalidate travel insurance policies.

Tunisia has criticised the UK’s travel advice, saying that it would destroy the country’s tourism, which is one of Tunisia’s main sources of income, and that it was “what terrorists want”.

Foreign Secretary Philip Hammond said:

“Since the attack in Sousse the intelligence and threat picture has developed considerably, leading us to the view that a further terrorist attack is highly likely.

“The Tunisian investigation into those behind the Sousse attack and that on the Bardo museum earlier this year is ongoing and the Tunisians have made clear they want to track down further individuals who they suspect may have links to this attack.

“While we are working with the Tunisian authorities to further strengthen those measures, we judge that more work is needed to effectively protect tourists from the terrorist threat.

“Taking all these factors together we judge it is right and prudent to make this change. We have not taken this decision lightly but our first priority will always be the safety of our citizens.

“In the days and weeks ahead, we will continue to keep the situation under close review and to work with the Tunisians to further understand the threat and to strengthen their security response to it.”