AMMAN: The Kurdish-led Syrian Democratic Forces (SDF) are gaining ground in their advance toward the border city of Azaz despite Turkish shelling on their positions, a commander with the SDF told Syria Direct on Monday.

“The Turkish strikes have not and will not affect us, and the proof is that we're still advancing,” Jaish al-Thuwwar spokesman Tareq Abu Zeid told Syria Direct Monday. Jaish al-Thuwwar is a member of the SDF coalition.

The SDF captured two villages from rebels over the past two days in the belt of opposition territory stretching 25km from Nubl and Zahraa north to Azaz, 6km from the Turkish border, backed by heavy Russian airstrikes. They are moving northeast up the stretch of territory and aim to take Azaz, which Turkish Prime Minister Ahmet Davutoğlu said his country would not allow to fall into Kurdish hands, reported state-owned Anadolu Monday.

“The world has to realize that Turkey will not allow Azaz to fall,” Davutoğlu was quoted by Anadolu as saying on Monday.

“For the moment, YPG elements have been driven out from Azaz’s surroundings,” the premier said, adding that the YPG is an “open instrument of Russia.”

Rebels and Turkey fear that the SDF, a force primarily made up of the YPG (Kurdish People's Protection Units), is moving one step closer to connecting Afrin and Kobani cantons by capturing this stretch of territory in northern Aleppo. The YPG is the armed wing of the PYD, considered by Turkey to be the Syrian branch of the PKK. Turkey, the United States and Europe list the PKK as a terrorist group.

Turkish artillery bombed SDF positions around Azaz over the weekend in an attempt to halt their advance, killing 29 fighters, reported Turk Press Sunday. Turkey’s official position, according to Anadolu, is that Ankara is shelling positions around Azaz “in response to artillery strikes on Turkey,” without elaborating further.

But Turkey’s artillery strikes are not going to stop the SDF advance, and rebels currently engaged in fighting the coalition’s march to the north do not have the weapons to stop it, said a rebel commander.

“Whether it's Turkey or someone else, the artillery strikes aren't enough, if the opposition is still to be deprived of weapons by the international community at the same time that weapons are flowing freely to the Kurdish militias,” a commander with the rebel Feilaq a-Sham brigade that is fighting the SDF in north Aleppo told Syria Direct Monday.

The commander, who requested anonymity, conceded that the Turkish bombings “might impede the attackers' progress for a time.”

In response to Turkey shelling the SDF, an American-backed ally, the White House responded with Vice President Joe Biden urging “Turkey to show reciprocal restraint by ceasing artillery strikes in the area,” according to a statement on Sunday. Washington supports the SDF with weapons and airstrikes in Hasakah province.

In addition to the YPG, the SDF coalition also includes Jaish al-Thuwwar, an umbrella group of former FSA-affiliated brigades. Its stated goal, according the announcement of its formation last fall, is to fight “the Islamic State and its sister organizations.” The group did not clarify what it means by “sister organizations.”

While the SDF's Jaish al-Thuwwar claims to be a rebel group, pro-opposition journalists and rebels in Aleppo view the outfit as a Kurdish proxy due to its alliance with the YPG. Because of the YPG's coexistence with the regime in the Hasakah province, rebels further accuse the SDF of tacit cooperation with the regime there as well as in Aleppo. Such assertions are bolstered by evidence of Russian airstrikes apparently assisting SDF/Jaish al-Thuwwar advances in Aleppo.

Jaish al-Thuwwar consistently maintains that it is part of the Syrian revolution, with a spokesman expressing his brigade's “willingness to unite” with FSA-affiliated rebels in a statement to pro-opposition Smart News last week.

The Turkish assaults on Kurdish and allied forces around Azaz is rallying public opinion for the SDF’s campaign to take the border city, Rauj Afrini, alias of a Kurdish citizen journalist in Afrin, told Syria Direct Monday.

“Some Kurds were against the idea of a new campaign, but after the Turkish strikes on the YPG they've become more sympathetic with their cause.”