Islamic State fighters withdrew from frontlines with Syrian rebel forces north of Aleppo on Wednesday as they 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, also known as Isis, 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, 20km (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 (Islamic State) 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The opposition source said Islamic State had withdrawn from the area quickly, and Free Syrian Army (FSA) factions had filled the void.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 the one being waged further east by a US-backed group, the Syria Democratic Forces (SDF), which includes the Kurdish YPG militia.
The Syrian army, backed by Russian air strikes, has also advanced against Islamic State since last week.
The FSA rebels are fighting separate conflicts with both the SDF and Assad, their main enemy.
Ten dead in air strikes
Air strikes in rebel-held districts of the city of Aleppo have killed at least 10 people and left many others wounded, Syrian opposition activists said.
They say one of the strikes on Wednesday hit near the Bayan hospital in the Shaar neighbourhood of the contested city.
The Syrian Observatory for Human Rights, a Britain-based opposition monitoring group, said at least 10 were killed, including children.
The Local Coordination Committees, which also closely follows the conflict in Syria, also reported the strikes, saying they resulted in multiple casualties.
The northern city of Aleppo has seen an uptick in violence in the last 48 hours.
Government forces are pounding rebel-held eastern parts of the city with strikes from the air while rebels are shelling western, government-held parts of the city.
Agencies