"It's a friggin' mess," one official said.
These fighters are part of the original band of 54 fighters sent into Syria. Their compound, which they share with another moderate opposition group known as Division 30, was attacked on July 31. That attack was repelled with the help of U.S. air strikes.
CBS News' Martin reports that in the late July attack, one Pentagon-trained fighter was killed and eight Division 30 fighters were wounded. 30 of the attackers, believed to be al-Nusra, were killed. It's not clear how the five were captured except that it was some time after the attack on the compound.
At a hearing before the Senate Armed Services Committee in early July, Defense Secretary Ash Carter disclosed that a $500 million program to train 15,000 Syrian opposition fighters had gotten off to an embarrassingly slow start -- with just 60 recruits in training.
"I say the number 60 and I can look out at your faces and you have the same reaction I do, which is that's an awfully small number," Carter admitted.
Carter had said 7,000 Syrians volunteered, but they first must go through a screening process designed to weed out extremists and those who want to use American training and equipment not against ISIS, but against the Syrian regime of Bashar Al Assad -- a fight the U.S. wants no part of.
Some who make it through the screening quit the training and go home. Said one U.S. official, "We are failing miserably."
U.S. expanded its combat in Syria, launching airstrikes Friday to defend rebels under attack by the Nusra Front.
Capt. Jeff Davis says this is the first time the U.S. conducted defensive strikes against anyone other than Islamic State of Iraq and Syria (ISIS) militants in Syria. Under current rules, the U.S. can conduct offensive strikes against ISIS, not Assad regime forces or others.
Meanwhile, a report by an independent monitoring group released Monday said U.S.-led airstrikes targeting ISIS have likely killed at least 459 civilians over the past year.
The report by Airwars, a project aimed at tracking the international airstrikes targeting the extremists, said it believed 57 specific strikes killed civilians and caused 48 suspected "friendly fire" deaths. It said the strikes have killed more than 15,000 ISIS militants.
In addition, the U.S. and Turkey are considering carving out a portion of northern Syria to become a haven or de facto safe zone for refugees and Western-backed rebels.
However, the White House is adamant that any joint efforts will not include the imposition of a militarily enforced no-fly zone.
Capt. Jeff Davis, a Pentagon spokesperson, underscored last week that they will not be working on a no-fly zone, and added that their recent talks with Turkey are an attempt to "deepen our cooperation, broadly."
The two countries have agreed to the shared goal of establishing an "ISIL-free zone" to ensure "greater security and stability along Turkey's border with Syria," a senior Obama administration official told CBS News, using an alternate acronym for the Islamic State of Iraq and Syria (ISIS).