The Russian warplanes struck a town in the countryside of the rebel-held Idlib province in northwestern Syria on Saturday, a war monitor reported.
The airstrikes targeted the Khan Sheikhun in the countryside of Idlib, killing at least two people and wounding four others, said the Syrian Observatory for Human Rights.
This comes amid shelling and battles between the Syrian army and the rebels in the southern countryside of Idlib and the nearby northern countryside of Hama province in central Syria.
There has been no independent confirmation of the airstrike.
Areas in the countryside of Hama, Idlib and the western countryside of Aleppo are included in the de-escalation zones deal which was reached between Russia and Turkey in September 2018.
The deal failed to materialize as the al-Qaida-linked Hayat Tahrir al-Sham (HTS) group expanded in Idlib and started attacks on Syrian military positions instead of withdrawing from the designated zone which combines Idlib with Hama and Aleppo countryside as well as mountain areas in the eastern countryside of Latakia province.
The military operation started in the aforementioned areas in late April 2019.