At least seven children and two pregnant women were killed in an air strike on Syria's rebel stronghold province of Idlib on Tuesday, a monitor said.
The strike, which hit the town of Khan Sheikun, in the south of the province, appeared to have been carried out by Syrian government ally Russia, the Syrian Observatory for Human Rights monitor said.
The Britain-based group, which relies on a network of sources inside Syria for its information, says it determines what planes carried out raids according to their type, location, flight patterns and the munitions involved.
Russia began its air campaign in support of the government in September 2015, saying it was targeting "terrorists."
"The strike hit a street where children were playing. Three of the dead children were from one family and were visiting their grandfather,"Observatory director Rami Abdel Rahman said. He said the dead children were four girls and three boys, but did not immediately have each of their ages.
Idlib province is mostly controlled by a rebel alliance known as the Army of Conquest, which groups Islamist factions with jihadists of the Fateh al-Sham Front, formerly Al-Qaeda's Syrian affiliate.Fateh al-Sham is blacklisted by the United Nations and the United States as a "terrorist organisation" and Russia says its fighters are a legitimate target.