Air strikes killed 23 people at a tourism spot in northwest Syria on Friday, the Syrian Observatory for Human Rights said, on the last day of a ceasefire announced by the Syrian army.
The air strikes hit a riverside area in the town of Darkush, near the Turkish border, in western Idlib province. Idlib province and city are strongholds of rebel groups including the al Qaida-linked Nusra Front.
The dead and injured had come from towns around the province to enjoy the Eid holiday weekend, witnesses and the Observatory said.
The death toll, which included 10 women and two children, is likely to rise due to the number of severely injured people, the Observatory said.
A 72-hour ceasefire was announced by the Syrian army on Wednesday, but rebels and the Observatory said there had been little let-up in the violence.