The Pentagon on Friday said a group of US-trained Syrian gunmen of the ’Train-and-Equip’ program had handed over ammunition and equipment to Al-Qaeda’s affiliate in the country, the Al-Nusra Front.

The Pentagon on Friday said a group of US-trained Syrian gunmen of the 'Train-and-Equip' program had handed over ammunition and equipment to Al-Qaeda's affiliate in the country, the Al-Nusra Front, allegedly in exchange for safe passage.

The startling acknowledgement contrasted with earlier Pentagon denials of reports that some trained gunmen had either defected or handed over gear.

"Unfortunately, we learned late today that the NSF (New Syrian Forces) unit now says it did in fact provide six pickup trucks and a portion of their ammunition to a suspected Al-Nusra Front (group)," Pentagon spokesman Captain Jeff Davis said.

Colonel Patrick Ryder, a spokesman for Central Command (CENTCOM), which is overseeing efforts against the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group in Iraq and Syria, said the gunmen had handed over the gear in exchange for safe passage in the Al-Nusra operating area.

"If accurate, the report of NSF members providing equipment to Al-Nusra Front is very concerning and a violation of Syria train-and-equip program guidelines," Ryder said.

Ryder added that the pickup vehicles and ammunition represented about 25 percent of the equipment issued to the group by the US-led coalition.

"We are using all means at our disposal to look into what exactly happened and determine the appropriate response," Ryder said.

A defense official told AFP that according to the gunmen, there had not been any defections, but he stressed: "We only know what they have told us."