Strikes by Syrian government jets on a besieged rebel stronghold near the capital Damascus on Thursday killed at least 60 civilians, a war monitor reported.
The fatalities in the region of Eastern Ghouta included 16 children, the Syrian Observatory for Human Rights added. The deadliest strikes targeted a market in the town of Arbeen, leaving at least 22 civilians dead, the Britain-based watchdog said.
Meanwhile, the BBC reported that Syrian Kurdish fighters captured the last two members of an Islamic State cell that, according to U.S. officials, had beheaded over 27 Western hostages. The cell, consisting of four men from London, was nicknamed "the Beatles."
The latest death toll brings the number of civilians killed in four days of government airstrikes on Eastern Ghouta to 210, according to the Observatory. At least 700 others have been wounded over the four days.
Eastern Ghouta, which is located on the eastern outskirts of Damascus, has been under siege by Assad's forces for more than four years. A total of 400,000 people in the region have been largely cut off from humanitarian aid since 2013.
Earlier on Thursday, more than 100 fighters aligned with Syrian President Bashar Assad were killed after U.S.-led coalition and coalition-backed local forces thwarted a large, apparently coordinated attack.
The heavy death toll underscored the large size of the attack, which the U.S. official said included about 500 opposing forces, backed by artillery, tanks, multiple-launch rocket systems and mortars. The official spoke to Reuters on condition of anonymity.
No American troops were killed or wounded in the incident, officials said.
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