Air strikes by Syrian government and Russian forces killed at least 20 people in rebel-held northwestern Syria on Saturday, activists and the Syrian Observatory for Human Rights said.
The attacks hit five villages in the Idlib region of the northwest, part of the last major territorial foothold of the insurgency against President Bashar al-Assad.
Russian jets killed at least nine people in an attack that hit a market in the village of Balyoun and another four people in a strike on the village of al-Bara, the Observatory said.
Five more people were killed in a barrel bomb attack by Syrian government helicopters on the village of Abdita, the Observatory said. Barrel bombs killed two more people in the villages of Jebghas and Tel Minis, it added.
Syrian state media carried no reports of military operations by the Syrian army or its Russian ally in those areas on Saturday.
The Observatory said eight children were among the dead.
Russia and Turkey, which backs the Syrian opposition and has troops on the ground in Idlib, brokered a ceasefire in the northwest in August but attacks have continued since then.
At least 11 people were killed in Syrian government air strikes that hit two outdoor markets on Monday, the civil defence said.
President Bashar al-Assad has vowed to recover "every inch" of Syria, which descended into a multi-sided conflict after the eruption of protests against his rule in 2011.