Nineteen civilians, including seven children, were killed in overnight airstrikes on Syria’s Idlib, said the Syrian Observatory for Human Rights on Wednesday.
Suspected Russian strikes targeted a residential district of the Maarshurin town in rebel-held Idlib in northwestern Syria, it added.
"Suspected Russian airstrikes targeted several houses in Maarshurin," said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.
He said 13 members of a single family were among the dead.
Idlib’s civil defense, a rescue service known as the White Helmets which operates in rebel territory, said fierce bombing after midnight killed 19 people.
The Observatory said 25 others had been injured.
There was no immediate comment from the Syrian regime forces. The Russian defense ministry later on Wednesday denied that its jets had carried out the strikes.
Residents of Maarshurin were still working on Wednesday morning to clear rubble from buildings hit in the bombardment, an AFP photographer reported.
One had been completely flattened and blood stained the rubble.
"These are all civilian homes," said resident Zahed Abu Abdo.
The Observatory said more than 25 people were wounded in the strikes, some of whom were in critical condition.
The Britain-based war monitor relies on a network of sources inside Syria and says it determines whose planes carry out raids according to type, location, flight patterns and munitions used.
Russia has been carrying out airstrikes in support of President Bashar Assad's regime since 2015.
Idlib province is one of four regions of Syria which are supposed to be safe areas under a deal agreed by Russia, fellow regime ally Iran, and rebel backer Turkey in May.