At least nine civilians were killed on Tuesday when airstrikes targeted a town in the rebel-held province of Idlib in northwestern Syria, a monitor group reported.

The airstrikes targeted the Khan Sheikhun area in Idlib countryside, killing seven children and two pregnant women, the report said.

The UK-based watchdog group said the death toll could likely rise due to the large number of critically wounded people, including children.

The Observatory, in its report, spelled no details on the identity of the warplanes, with other activists suggesting they were Russian.

The Observatory and other activists have repeatedly accused Russia of carrying deadly airstrikes against civilian areas in rebel-held towns and cities, a claim always denied by Moscow.

Much of Idlib has fallen to the rebels over the past two years, with the government holding only two Shiite towns in the countryside of that province.

Idlib has emerged as an attraction place for rebels, who are defeated and dislodged from areas they had controlled, and the government forces in Syria have given the rebels safe passages to Idlib on many occasions, in exchange of leaving areas in Aleppo they controlled, or the surrounding of the capital Damascus.