Turkish soldiers stand guard at the border with Syria where dozens of Isis fighters have been caught trying to flee after Raqqa was re-taken

Hundreds of Islamic State fighters have exploited a deal struck with American-backed Kurdish soldiers to escape from Syria, using smuggling routes to enter mainland Europe.

Some were able to openly leave Raqqa, the capital of their self-proclaimed caliphate, under an arrangement devised to help civilians escape before the fall of the city. However, when Raqqa was re-taken by western-backed coalition forces in October, hundreds more, many of them European jihadists, managed to flee the city. Dozens have since been caught trying to cross the border into Turkey.

In an exclusive interview with The Times, one of those arrested said that hundreds of Isis fighters had exploited the well-established smuggling routes into Turkey. Saddam al-Hamadi, 26, said: “I took advantage of that movement during the