Airstrikes carried out by the US-led coalition killed 25 civilians in Syria's northern province of Hasakah on Tuesday, state news agency SANA reported.
The airstrikes targeted civilian homes in the village of Fadel in the city of Shadadi, southern Hasakah, said the report, adding that women and children were among the victims as tens of others were wounded.
The report slammed the attack as a "massacre," saying the operations of the US-led coalition in Syria are "illegitimate."
The US has been backing the Kurdish-led militant groups in northeastern Syria. On Tuesday, the US-backed Syrian Democratic Forces (SDF) launched a new offensive on Islamic State (IS) militants in the eastern countryside of Deir al-Zour province in eastern Syria near the Iraqi border.
The SDF stripped IS of their de facto capital of Raqqa in northern Syria late last year while the Syrian government recaptured large swaths of territory from IS in Deir al-Zour.
The US-led coalition started its operations in Syria in 2014, with the government criticizing such coalition for targeting civilians while urging the UN to put an end to the coalition's operations in the war-torn country.