Barrel bombs dropped on civilian areas in Syria's northern Aleppo province on Saturday reportedly killed at least 70 people and wounded scores of others, including many at a packed market in a town held by the Islamic State (IS).
Syrian regime helicopters reportedly dropped three barrels filled with explosives in two separate, successive attacks. A barrel that hit the rebel-controlled Al Shaar neighborhood in Aleppo killed at least 12 people, including three children and four women, according to the Syrian Observatory for Human Rights (SOHR), a UK-based monitoring group.
The other attack devastated the bustling market of Souk al-Hal in the Islamic State-held town of al-Bab in Aleppo's countryside, killing at least 59 people, according to the SOHR, and leaving dozens wounded. The casualty count is expected to rise, and the SOHR called it one of the worst massacres perpetrated by Syrian President Bashar al-Assad's army this year.
Graphic video footage shared by the Shahba Press Agency shows a vehicle on fire in the aftermath of the Al Shaar bombing. Volunteers can be seen carrying away several dismembered lifeless bodies from the blast site.
"The news of aerial bombing by Syrian helicopters on a civilian market area of the Aleppo neighborhood of Al Shaar deserves the most strong international condemnation," United Nations Special Envoy for Syria Staffan de Mistura said in a statement. Mistura also added that "indiscriminate" aerial attacks were unacceptable and responsible for "the overwhelming majority of the civilian victims in the Syrian conflict."
IS also confirmed the attack in a statement posted on Twitter, announcing that 50 people were killed in a "devastating massacre" committed by Syrian army helicopters.
Once Syria's commercial hub, Aleppo has been wrought with violence since mid-2012 in an ongoing battle between government and opposition forces.
On Sunday, IS fighters captured the town of Souran Azaz and the nearby villages of Hasya and Bel in Aleppo from moderate Syrian rebel groups, according to the Associated Press. The villages are near a border crossing with Turkey.
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The SOHR reported that the fighting in the area killed 31 rebels and 22 IS members. IS has been fighting over territory with rebel groups in Aleppo since early last year.
Meanwhile, rebels reportedly shelled a government-held neighborhood in Aleppo, killing 12 people, according to Syria's state news agency SANA. The SOHR said the shelling resulted in eight deaths.
More than 220,000 people have been killed in Syria since the start of the uprising against Assad in March 2011.
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The Associated Press contributed to this report.