Most of the dead in the Idlib strikes were fighters of the former al-Qaeda affiliate Fateh al-Sham
Syrian government air strikes killed at least six civilians, including four children, in Aleppo province on Thursday, despite a fragile two-week-old truce, a monitor said.
And in neighbouring Idlib province, at least 22 militants were killed in air strikes over the past 24 hours, the Syrian Observatory for Human Rights said.
Some of the raids were carried out by government aircraft, others by aircraft of the US-led coalition, the Britain-based monitoring group said.
The civilians were killed early on Thursday when a government air strike hit a house in the village of Babka in the west of Aleppo province.
It said the death toll could rise because a number of the wounded were in serious condition.
Most of the dead in the Idlib strikes were fighters of the former al-Qaeda affiliate Fateh al-Sham. Two of the group's commanders were among 16 fighters killed in a coalition strike on their convoy on Wednesday, the Observatory said.
Earlier, three allied militants were killed in a government raid. Later, three Fateh al-Sham fighters were killed in apparent drone strikes.
The Observatory says it determines whose planes carry out raids according to their type, location, flight patterns and the munitions involved.
The strikes came despite a nationwide truce brokered by regime supporter Russia and rebel backer Turkey that has been in place since 30 December.
The truce does not include Fateh al-Sham, formerly known as al-Nusra Front, or the Islamic State (IS) group.
The ceasefire has brought quiet to large parts of the country, but sporadic violence has continued in some areas, threatening the fragile agreement.
Idlib province is largely controlled by a powerful alliance of opposition forces known as the Army of Conquest, which is dominated by Fateh al-Sham.
More than 310,000 people have been killed in Syria since the conflict began with anti-government protests in March 2011.
On Wednesday, a Russian foreign ministry source said that peace talks were scheduled for 23 January in the Kazakh capital Astana, a date previously floated by Turkish officials.
"At this time there is no indication that the meeting will be postponed. The date of January 23 is set," the source said, adding that work was underway to compile a list of participants.