“The central priority here was the protection of civilian lives and the arrangement was reached by our partners and their local affiliates,” Pentagon spokesman Eric Pahon told the Turkish Anadolu Agency on Tuesday.
The release was organized by the US-led international coalition to defeat ISIS's local partners, the Syrian Democratic Forces (SDF) and was a bid to reduce civilian casualties in the fight for Raqqa.
"This was not a secret,” Col. Ryan Dillon, the spokesperson for the US-led international coalition to defeat ISIS said at a Pentagon press briefing on Tuesday, noting that the Coalition provided information in two separate press releases in October.
The SDF screened those who evacuated the city in an effort to detect ISIS combatants using digital screening technology provided by the coalition.
"As the civilians were coming out there was an agreement that was made that ISIS-aged males or civilians that came out would be screened and we would take biometrical data from them to see if they were in our system, if not, to be processed in that system,” Dillon explained.
Foreign fighters were supposed to be exempt from the deal.
Turkey worries that it and the world could be targeted by ISIS fighters who were allowed to leave the battlefield in Raqqa with their weapons.
"This work is shocking,” said Turkish Prime Minister Binali Yildirim on Tuesday.
Dillon explained the deal was organized between Raqqa Civil Council, SDF, and local tribal elders – with an officer from the coalition observing in a “non-active role.”
"We are not aware of and certainly can't corroborate the amount described in the story or the statements made by the bus drivers,” he added, referring to a BBC report published on Monday.
A convoy of "hundreds of IS fighters, their families and tonnes of weapons and ammunition" was brought out of the city, one of the convoy's drivers, Abu Fawzi, told the BBC. He estimated around 4,000 people, including women and children, were evacuated in a convoy that stretched 6 or 7 kilometres long.
The deal was made after four months of heavy fighting between ISIS and the SDF. It was to end the fighting in Raqqa.
The drivers claim they were misled by the SDF who promised to send its forces with the convoy that the ISIS militants booby-trapped, in case the deal went haywire.
"Even their children and women had suicide belts on," said Fawzi.
The coalition confirmed on Tuesday that it did not have personnel with the convoy on the ground, but it monitored from the air.
"We followed these buses as they departed the Raqqa area,” said Dillon.
Dillon explained the protection of civilians shaped the decision not to strike the convoy.
He reasoned that the deal was just movement out of Raqqa and not an escape for the fighters. “They were staying within Syria... so it was just a matter of time until we fought them again."
The convoy brought the fighters into ISIS territory in eastern Syria. From there, some paid smugglers to bring them to Turkey, according to the BBC report, which noted that foreign fighters were a large component of the convoy.
Dillon denied that large number of foreigners managed to flee Raqqa.
"In the course of that screening there were four foreign fighters that were identified and were detained by the SDF. Out of the 3,500 civilians that came out of Raqqa at that time less than 300 were identified and screened as potential ISIS fighters,” Dillon told the Pentagon reporters.
While large in scale, the deal with ISIS is not unprecedented.
A “forced withdrawal” of ISIS fighters contributed to the SDF retaking Tabqa in March.
"Approximately 70 ISIS fighters conceded to the SDF's terms, which included the dismantling of IEDs surrounding the dam, the surrender of all ISIS heavy weapons, and the forced withdrawal of all remaining fighters from Tabqa City," said an SDF statement in May.
The SDF announced the "total liberation" of Raqqa on October 20. ISIS had referred to the city as its capital.
