"Russian strikes this morning targeted the Hurras al-Deen group and Ansar al-Tahwid in eastern Idlib... killing nine jihadists," said the Britain-based Syrian Observatory for Human Rights, adding eight others were wounded.
Six of the dead were members of the Al-Qaeda linked Hurras al-Deen, a group which is also targeted by the US-led coalition.
Moscow is a key ally of Syria's President Bashar al-Assad in the country's civil war, and despite an Idlib ceasefire deal reached on August 31, the province has continued to be targeted by Russian air attacks.
Russia-backed regime fighters have for weeks been chipping away at the edges of the province bordering Turkey that is the last jihadist stronghold outside of Assad's control.
Hayat Tahrir al-Sham - a group led by Syria's former Al-Qaeda affiliate - extended its administrative control over the whole of Idlib in January, but other rebel factions remain present.