At least 15 civilians were killed on Tuesday when warplanes with the US-led anti-terror coalition struck areas under the Islamic State (IS) control in Syria's northeastern province of al-Hasakah, a monitor group reported.
The strikes targeted the IS-held city of Shaded in the countryside of al-Hasakah, said the Syrian Observatory for Human Rights.
The Britain-based watchdog group said the death toll will likely rise due to the number of critically wounded people, Xinhua reported.
The US-led coalition has been striking IS positions in Syria for over a year, but Syrian officials have been slamming the strikes as "ineffective", while hailing the air support by the Russian air force, a main ally of the Syrian government forces in recent crushing offensive against militant groups across the country.
Still the Kurdish fighters is Syria, with the People's Protection Units (YPG) and the Kurdish Democratic Union (PYD), have claimed that the US coalition is greatly aiding them in their fight against the IS in northern Syria, mainly in the northern province of Aleppo.
The Observatory, which relies on a network of activists on ground, said on Tuesday that the Kurdish-backed Syrian Democratic Forces (SDF) captured the town of Ayn Issa from the jihadi groups in northern Aleppo, bringing them close to the town of Mare, the last town whose capture by the SDF will put them in direct confrontation with the IS-held areas in northern Aleppo.
The Syrian army has also been advancing in northern Aleppo, amid reports of an undeclared coordination between the SDF and the army in the push against radical groups in northern Aleppo.