The Syrian Observatory for Human Rights, a Britain-based monitor, said those killed included two children.

The raids took the lives of three civilians including a boy on the outskirts of the town of Kafranbel, and seven including a girl in the town of Tal Hawash, Observatory chief Rami Abdel Rahman said.

Russia and rebel-backer Turkey in September inked a buffer zone deal to prevent a massive regime offensive on the Idlib region, near the Turkish border.

But the region of some three million people has come under increasing bombardment since former Al-Qaeda affiliate Hayat Tahrir al-Sham took full control of it in January.

The latest air raids came as two days of talks on ending the war in Syria -- sponsored by Russia, fellow regime ally Iran, and rebel backer Turkey -- concluded in Kazakhstan.

In a statement released by the three countries after the meeting, they expressed concern about HTS extending its influence in Idlib.

They stressed their "determination to continue cooperation in order to ultimately eliminate" HTS and the Islamic State group, the statement said.

Syria's war has killed more than 370,000 people and displaced millions since the conflict began with the repression of anti-government protests in 2011.