Russia escalating Syria war by targeting moderate opposition: US

Russia is escalating Syria's civil war by targeting the moderate opposition, US Defense Secretary Ash Carter said on Monday, comparing Moscow's effort to bolster Syrian President Bashar al-Assad to tethering itself to a sinking ship.

"By taking military action in Syria against moderate groups targets, Russia has escalated the civil war," Carter said in a speech during a trip to Spain.

The United States, France and Britain say the Russian air strikes are aimed at propping up Assad after recent rebel advances. "They are backing the butcher Assad, which is a terrible mistake, for them and the world," British Prime Minister David Cameron said.

Residents in the Syria province of Homs reported air strikes on Sunday they believed were carried out by Russian jets, in an area controlled by factions fighting under the umbrella of the rebel Free Syrian Army, not Islamic State.

Meanwhile, Kremlin spokesman Dmitry Peskov told journalists on Monday, Russia's operations in Syria are aimed at supporting the Syrian army and target terrorists and extremists there,

"The aim of our operations lies in providing support to the Syrian military's offensive in their struggle with terrorist and radical organizations and forces," Peskov said.