Islamic State fighters withdrew from frontlines with Syrian rebel forces north of Aleppo on Wednesday as the rebels mounted a counter attack against the jihadist group near the Turkish border, an opposition source and monitoring group said.
The sudden withdrawal from villages around the rebel-held town of Marea points to the pressure Islamic State is feeling from offensives being waged by other enemies further east, the Syrian Observatory for Human Rights monitoring group said.
Islamic State had managed to besiege the rebel-held town of Marea in a significant advance late last month, stranding thousands of civilians there and prompting a US-led coalition to air drop weapons to rebels, rebel sources said.
Rebel fighters in Marea broke the siege on Wednesday when they captured the village of Kafr Kalbin on the road linking Marea with Azaz, 12 miles to the northwest at the border with Turkey. The advance was preceded by a rebel statement saying they were uniting their ranks.
"It seems they [IS] can't keep several fronts open at the same time. It is a strategic area, they were on the verge of entering Azaz," Observatory Director Rami Abdulrahman said. The opposition source said Islamic State had withdrawn from the area quickly, and Free Syrian Army factions had filled the void.
FSA rebels fighting Islamic State north of Aleppo have received military assistance from states opposed to President Bashar al-Assad.
Their battle with Islamic State is separate to one being waged further east by a US-backed group, the Syria Democratic Forces (SDF), which includes the Kurdish YPG militia.
In that battle, the SDF is ready to enter the Islamic State-held city of Manbij at will but is being cautious due to the presence of civilians there, a spokesman said on Wednesday.
"Any moment that we want to enter it, we can, but because of the presence of civilians... we are being cautious about entering the city," Sharfan Darwish of the Manbij Military Council told Reuters.
"I can say that the matter of liberating Manbij is settled," he said. "When the time comes we will enter it of course."
The offensive includes the powerful Kurdish YPG militia, which controls wide areas of northeastern Syria, and its Arab allies. The goal of the offensive is to ultimately dislodge IS from the last stretch of the Syrian-Turkish frontier — a top priority of the US-led coalition fighting the group in Iraq and Syria.
"There is news about many Daesh [IS] members escaping and evacuating some areas of Manbij and booby-trapping them," Darwish said. "Our forces are now on the outskirts of the city. The campaign continues."