At least five civilians were killed by Russian and Syrian government warplanes that targeted Syria's northwest as residents marked the holiday of Eid al-Fitr.
A local source told Anadolu Agency the five people died on Wednesday in air attacks targeting the town of Kansafra and three villages in Idlib.
The UK-based Syrian Observatory for Human Rights war monitor put the death toll at 10, saying two children were among those killed.
Another civilian died in shelling by government forces on the northern Hama countryside, also held by rebels, said the group, which relies on a network of sources on the ground in Syria.
Government air attacks also hit a motorcycle in the Idlib town of Maaret al-Numan, killing a woman and her two children, said the Observatory.
Wednesday's attacks come amid an escalation in violence in the country's northwest that is held by Syria's former al-Qaeda affiliate Hay'et Tahrir al-Sham.
A September deal was supposed to avert a full-out government offensive on Idlib province and adjacent areas, home to about three million people, nearly half of whom have been displaced from other parts of Syria.
But the government and its ally Russia have since late April ramped up deadly air raids and rocket fire on the region, and fighters have clashed on its edges.
The bombardment of Idlib province and neighboring areas has killed more than 300 people since late April, according to the Observatory.
It also displaced nearly 270,000 people in May alone, according to the United Nations.
A total of 24 health facilities and 35 schools have been hit in the latest escalation, according to the UN's humanitarian office.
Analysts predict that President Bashar al-Assad and his allies will continue to chip away at the area, but not unleash a major assault that would create chaos on Turkey's doorstep.
The conflict in Syria has killed hundreds of thousands of people since it started in 2011 with millions displaced.
Source: Al Jazeera