Anti-IS coalition denies collusion in 'secret' Raqqa Islamic State evacuation deal

The BBC published a lengthy expose on Monday, accusing the coalition of turning a blind eye to the "secret deal" with allied forces that let IS fighters and their families escape from Raqqa in a convoy last month.

The British government said on Tuesday that the "arrangement was made by local partners to reduce civilian casualties" in the city, which was recaptured by the coalition-backed Syrian Democratic Forces on October 17.

The spokesman for the US Central Command said the deal was not carried out in confidence.

"This was a local solution to local issue. Coalition did not fully agree, but respected our partner's decision," he said.

Last month, the coalition released a statement to announce the move, but was careful to stress that the SDF had struck the deal.

"The arrangement is designed to minimise civilian casualties and purportedly excludes foreign Daesh terrorists as people trapped in the city continue to flee the impending fall of Daesh's so-called capital," the statement said, using an Arabic acronym for IS.

"We do not condone any arrangement that allows Daesh terrorists to escape Raqqa without facing justice, only to resurface somewhere else," it added.

According to the BBC investigative report, the deal allowed some of IS' most senior members and dozens of foreign fighters to escape along with weapons and ammunition and travel as far away as Turkey.

The report includes interviews with drivers who carried the militants to safety in a convoy of trucks, buses and IS vehicles and footage showing the trucks loaded with armed men.

IS has in the space of a few weeks seen its "caliphate" shrink to a small rump and lost major cities such as Mosul in Iraq, and Raqqa and Deir az-Zour in Syria.