At least three civilians from the same family were killed when Russian warplanes struck the outskirts of the northwest Syrian city of Idlib on Saturday, a war monitor said.
Russia has over the years repeatedly struck Syria's last main opposition bastion, but attacks killing civilians had been limited this year until an uptick in violence in late June.
"Russian air strikes this morning" to the west of the city left "three dead from the same family... and six people wounded", the Syrian Observatory for Human Rights said, adding rescue teams were still at work removing rubble.
Four strikes hit the area where rebel bases are also present, added the Observatory, a Britain-based group which relies on a network of sources on the ground in Syria.
With Russian and Iranian support, the regime of Syrian President Bashar al-Assad has conquered much of the territory won by rebels early in the conflict.
The last pockets of armed opposition to the Assad government include swathes of the rebel-held Idlib province, some of which is controlled by anti-Assad jihadist groups.
Syria's 12-year-long war broke out after the repression of peaceful anti-government demonstrations escalated into a deadly conflict that pulled in foreign powers, mostly on behalf of Assad. The war also led to the rise of the Islamic State group, which fought the Syrian rebels as well as pro-Assad forces.
The war has killed more than half a million people and displaced millions.
'Uptick' in Russian violence
Since 2020, a ceasefire deal brokered by Damascus ally Moscow and rebel-backer Ankara has largely held in Syria's northwest, despite periodic clashes.
However, in an uptick in violence, Russian air strikes killed at least 13 people in Idlib province on June 25, in what the Observatory said at the time was the deadliest such attack on the country this year.
At least nine civilians, including two children, were among the dead -- six of them killed at a fruit and vegetable market in Jisr al-Shughur.
On June 28, Damascus's defence ministry said Syrian and Russian forces had launched air strikes on rebel bases in the Idlib region.
The operation came "in response to daily and repeated attacks... on civilians" in residential areas in nearby Hama province, the ministry had said.
It did not specify the date of the bombardment, but the announcement came a day after Russian air strikes killed eight HTS-affiliated fighters, according to the Observatory.
The rebel-held Idlib region is home to about three million people, around half of them displaced from other parts of the country.