Syrians searching for survivors amid the debris following air strikes on the rebel-held town of Atareb in Syria's northern Aleppo province on Monday. At least 53 people, including children, were killed despite a "de-escalation zone" in place there, the Britain-based Syrian Observatory for Human Rights said, adding that it was not immediately clear if the strikes on Atareb had been carried out by Syrian warplanes, or those of Damascus' ally Russia. Atareb is in the west of Aleppo province, in an area that is part of a "de-escalation zone" agreed under a deal earlier this year between Syria's allies Russia and Iran, and rebel backer Turkey. Russia, a key ally of Syrian President Bashar al-Assad, began a bombing campaign in support of his government in 2015. Since then, with Moscow's support, the government has recaptured large swathes of territory from opposition forces. Moscow has steered the so-called Astana process that in May led to a deal to create four so-called "de-escalation zones" which have produced a drop in violence, but sporadic fighting and bombardment have continued, and promised humanitarian access has not materialised.