Group claims ISIS has taken to the air

A new report says the Islamic State of Iraq and Syria (ISIS) militants are taking to the sky.

The Syrian Observatory for Human Rights (SOHR), a U.K.-based organization which relies on an extensive network of sources and activists inside Syria, claims defected Iraqi military officers are teaching members of the terror group how to fly three commandeered fighter jets.

SOHR's sources say jets have been seen flying low over Syria's province, reports CBS News correspondent Holly Williams. ISIS did overrun and seize control of the al-Jarah air base in rural Aleppo, but it isn't clear how long ago.

"The people who live in the nearby areas of the airbase of al Jarrah informed SOHR activists that they saw a warplane taking off from al Jarrah airbase and flying at a low altitude over the area. It is worth mentioning that it is not the first time that the people witness an aircraft flying at a low altitude after taking off from al Jarrah airbase," said SOHR in its online report.

However, the U.S. military said on Friday it was unaware of ISIS flying fighter jets "in Syria or elsewhere," Reuters reported.

"We continue to keep a close eye on ISIL activity in Syria and Iraq and will continue to conduct strikes against their equipment, facilities, fighters and centers of gravity, wherever they may be," said Central Command spokesman Colonel Patrick Ryder, using another acronym for ISIS.

The Syrian army has reportedly conducted airstrikes on the facility in recent days, which could explain some of the reports of low-flying aircraft.

The claim from the SOHR comes a day after a series of terror attacks in the Iraqi capital of Baghdad, where ISIS militants are still inflicting deadly damage.

At least 50 people were killed in the Iraqi capital Thursday in a series of car bombs carried out by ISIS, as well as a mortar attack on a residential area.

In Syria, however, the battle for the key border town of Kobani has taken a new turn.

Just a few days ago ISIS was in control of a third of the town, but after intense U.S.-led airstrikes, including 53 over the last three days, there are reports that the militants are retreating.

Local Syrian fighters tell us they've begun coordinating the airstrikes with the U.S.

Kobani is strategically important -- it lies on the Turkish-Syrian border which is a conduit for smuggled weapons and fighters. But it's also become a very public test of whether U.S.-led airstrikes can be effective in halting the advance of ISIS militants.