Sixteen civilians, including three children, were killed on Monday in heavy bombardment across rebel-held Idlib province in northwest Syria, a monitoring group said.
In Khan Sheikhun, a town in the province's south, air strikes killed seven people, including two women and a child, the Syrian Observatory for Human Rights said.
The Britain-based Observatory said the raids were carried out by either Syrian or Russian aircraft.
Another seven people, including four women and two children, were killed in raids on Kafr Takharim, further north in the province.
Those raids hit three residential buildings, a local government building, and a stadium, shortly after midnight, AFP's correspondent in the town said.
In the morning, rescue workers were still trying to pull bodies out of the rubble.
"My sister's house was standing right here. She and her daughter are dead, along with another family," Abu Mohammad told AFP.
"There was no military base here. All the military positions are outside the town," the devastated man said.
Another man and a woman were killed in rocket fire in the nearby town of Kafr Awid.
Idlib province is controlled by the Army of Conquest, an alliance of rebel groups and jihadists including the Fateh al-Sham Front, which changed its name from Al-Nusra Front after breaking off ties with Al-Qaeda.
According to the Observatory, heavy bombardment has battered the northwest province in recent days.
Since Thursday, bombardment has killed 44 civilians, including 11 women, nine children, and one rescue worker.
Syria's conflict broke out in March 2011 with anti-government protests, but it has since evolved into all-out war pitting rebels, government forces, Kurds and jihadists against each other.