Islamic State captures major Syrian air base in northeast

Islamic State fighters captured a major military air base in northeastern Syria on Sunday, eliminating the last government-held outpost in a province otherwise dominated by the armed group, activists and state media said.

The U.K.-based Syrian Observatory for Human Rights (SOHR) said at least 346 Islamic State fighters were killed and more than 170 members of government forces had died since Tuesday in the fight over the Tabqa compound, making it one of the deadliest confrontations between the two groups since the start of Syria's war.

The base is the third in the area to fall to the extremists since last month as part of the Islamic State (IS) group's aggressive push to consolidate its hold on Syria's northern and eastern provinces, while also expanding the boundaries of its self-styled caliphate straddling the Syria-Iraq border.

The jihadis launched their long-anticipated offensive last week to seize the sprawling Tabqa facility, which houses several warplane squadrons, helicopters, tanks, artillery and ammunition bunkers, located some 25 miles from the group's stronghold in the city of Raqqa along the Euphrates River.

After several failed efforts to breach the walls in recent days, Islamic State fighters managed to punch through and storm the air base Sunday, SOHR said. Government warplanes carried out waves of airstrikes to try to beat back the attack, but those ultimately proved unable to stem the assault. Syrian state television said that after fierce battles, the military was “regrouping.”

In Raqqa city, an Islamic State stronghold, there was celebratory gunfire and several mosques announced through their loudspeakers that the base had fallen to the armed group and cheered "God is greatest," a witness told Reuters. IS fighters displayed the severed heads of Syrian army soldiers in the city square, the witness said.

Citing a military source, Syrian state television said there was a “successful evacuation of the airport” and that the army was continuing strikes on “terrorist groups” in the area, which it said had suffered heavy losses.

With Tabqa now in hand, the Islamic State group could focus on the battlefront in neighboring Aleppo province. The extremists have already captured at least a dozen towns and villages there in recent weeks, crushing mainstream Syrian rebels and advancing toward the city of Aleppo.

The group’s slow and steady push in northern and eastern Syria, as well as their lightning advance across Iraq, has brought under their control a stretch of territory running from Syria's northern border with Turkey as far as the outskirts of Baghdad in central Iraq. The group has declared a self-styled caliphate under its strict interpretation of Islamic law.

Early this month, the United States began launching airstrikes against the group in northern Iraq. Those operations mark the first American military involvement in the country since the last U.S. forces withdrew in 2011.

The more moderate Syrian opposition, which is fighting President Bashar al-Assad as well as the Islamic State group, has called for similar air raids against the extremists in Syria. The Obama administration has so far refused, wary of getting dragged into a bloody and complex civil war that the U.N. says has killed more than 190,000 people.

Wire services