A child was among at least 15 civilians killed in air strikes on an Al-Qaeda-held town in northwestern Syria on Friday, a monitoring group said.
Around 40 people were also wounded in the strikes on the town of Darkush, near the Turkish border, the Syrian Observatory for Human Rights said.
"At least 15 people were killed, including a child and six women," Observatory head Rami Abdel Rahman said.
Darkush is held by Al-Qaeda affiliate Al-Nusra Front and allied rebel groups, which control the northwestern province of Idlib.
The Britain-based Observatory had no immediate word on who carried out the strikes but said it was likely to have been either the Syrian government or its ally Russia, rather than the US-led coalition.
The Syrian army announced on Wednesday it would observe a 72-hour nationwide ceasefire for Eid al-Fitr.
It was unclear if Al-Nusra was included, but the Al-Qaeda affiliate and its jihadist rival the Islamic State group have been excluded from a broader truce brokered by Moscow and Washington in February.
The Kremlin said on Wednesday that President Vladimir Putin and his US counterpart Barack Obama had agreed to "intensify" military coordination in Syria.
The White House said the two leaders had "confirmed their commitment to defeating ISIL (IS) and the Al-Nusra Front."
More than 280,000 people have been killed in Syria since the civil war erupted in 2011.
It began with peaceful protests but swiftly escalated into an armed rebellion that has become increasingly dominated by jihadist groups