Ash Carter hits Russia for attacking US-backed rebel forces in Syria

He recalled that when the Russians first sent forces to Syria they said their purpose was to fight the Islamic State

Defence Secretary Ash Carter today criticised Russia for bombing US-backed rebel forces in Syria that he said were fighting the Islamic State group.

Carter told reporters at the Pentagon that the Russian attacks were "problematic" and said the Russian military misused a channel of communication with the US military that is intended to prevent unsafe US and Russian air operations over Syria. Another defense official, speaking on condition of anonymity because he was not authorised to publicly disclose details, said US officers used the hotline to urge a halt to the strikes but those requests went unheeded.

The phone line "wasn't professionally used" by the Russians, Carter said without elaborating.

Carter recalled that when the Russians first sent forces to Syria they said their purpose was to fight the Islamic State.

"That's not what they did. They mostly supported Assad and fueled the civil war," he said. "But here's a case where they actually attacked forces that were fighting ISIL, and if that was their intention that's the opposite of what they said they were going to do. If not, then it says something about the quality of the information upon which they make airstrikes."

Other officials said the attack, which included multiple waves of airstrikes, was aimed at a remote area near where the intersection of the Syrian, Jordanian and Iraqi borders. The officials said the Russians had not previously struck there. The anti-IS forces that were assembled there included fighters who have been trained and equipped by the US.

In a separate development, the US Central Command announced that it killed a total of six operatives of al-Qaida's affiliate in Yemen in three airstrikes earlier this month. The strikes were conducted against the group known as al-Qaeda in the Arabian Peninsula on June 8, 10 and 12.

"Al-Qaeda's presence has a destabilising effect on Yemen, and it is using the unrest in Yemen to provide a haven from which to plan future attacks against our allies as well as the US and its interests," Central Command said in a statement today.