Rebels call for U.S. airstrikes as Islamic State advances near Aleppo

With Islamic State militants pressing a dramatic new military offensive north of Aleppo, moderate rebels pleaded Monday for U.S. intervention to preserve rebel supply routes and prevent Syria’s biggest city from falling to the extremists.

Islamic State fighters were reported just six miles away from the Bab al Salameh border crossing across from Kilis, Turkey, a major portal for rebel weapons and for civilian food and other supplies.

Capturing the crossing point would cut off rebel forces in Aleppo, and rebels voiced fear that the Syrian government might abandon its positions in Aleppo, allowing Islamic State forces to move in without resistance.

Islamic State fighters exchanged artillery fire with rebels and set wheat fields ablaze in one village, Umm al Quraa, a conflagration that then spread to two other villages, according to reports from a media activist in Aleppo.

Meanwhile, rebel forces rushed to the area from Aleppo and Idlib province to counter the Islamic State advance. One group, Sukour al Jabal, which receives aid from the U.S.-backed Military Operations Center, reported destroying two Islamic State tanks and two large cannons using U.S.-supplied TOW anti-tank missiles.

The Islamic State offensive began Friday. Fresh from its conquest of Ramadi, the biggest city in Anbar province in Iraq, and the capture of Palmyra, a city in eastern Syria that’s home to some of the greatest Roman ruins in the Middle East, the Islamic State attacked rebels at three locations along a 30-mile front and captured three villages.

One day later, the Syrian government unleashed barrel bombs that opposition reports claimed killed upward of 100 civilians in Aleppo and al Bab, a city controlled by the Islamic State.

A spokesmen for the al Shamiah front, the umbrella group for rebels in the area, said the Syrian aerial offensive ended up helping the Islamic State advance, with government aircraft attacking the towns of Maria and Soran just as the Islamic State did the same.

Islamic State fighters were backed by Grad missiles and heavy artillery and used tanks in the initial attack, according to the spokesman, who asked to be identified by his nom de guerre, Abu Muhammad, and was interviewed in Aleppo via Skype. The Islamic State later deployed two explosives-laden armored vehicles as suicide bombs in Soran, he said. Those bombs wounded 30 rebels and forced the rebels to withdraw to al Kafra, a village about a mile away.

Simultaneously, Islamic State fighters attacked farther south, taking the village of al Hisya and part of Umm al Quraa. A third attack captured the village of Tel Ashaer, Abu Muhammad said.

The spokesman criticized the U.S.-led coalition for not bombing Islamic State convoys as they moved into position from Raqqa, the Islamic State’s capital, and al Bab.

“There were convoys of 15 to 20 vehicles each,” he said. “Only two coalition raids in the past three days would have been enough to stop the attack.”

A similar complaint was lodged by Salim Idriss, a rebel commander who once was the United States’ designated leader of rebel forces in Syria. At a news conference in Istanbul, he said the international coalition repeatedly had allowed Islamic State convoys to pass unhindered, most recently on Sunday, when he said a 60-vehicle convoy moved from Raqqa to Aleppo unmolested.

In Washington, Pentagon spokesman Army Col. Steven Warren said the U.S. military was aware that Islamic State convoys move around Syria, but he defended the lack of airstrikes, saying the U.S. priority “remains Iraq, where we have a willing partner on the ground.”

While the United States has used a clandestine CIA program to arm some rebels in Syria, it generally has not embraced most of the country’s armed opposition, much of which U.S. officials have accused of having ties to al Qaida or other Islamist forces.

“One of the things we’re doing (in Syria) is training the moderate opposition so that we can have a viable ground partner in Syria that will help us beat back ISIS,” Warren said, using an acronym for the Islamic State.

Civilian leaders of the Syrian opposition coalition also pleaded for U.S. airstrikes to stop the Islamic State advance.

Khalid Khoja, president of the Syrian Opposition Coalition, which the United States once recognized as the leading opposition group, called it “unacceptable that Syrians see the international coalition’s aircraft flying over our heads without bothering about Daash slaughtering them.” Daash is an Arabic acronym for the Islamic State.

McClatchy special correspondent Alhamadee reported from Reyhanli, Turkey; Gutman, from Istanbul. James Rosen contributed from Washington.