At least 39 civilians were killed Tuesday in suspected Russian air strikes on two markets in northern Syria, a monitoring group said.

The raids killed 16 civilians at a market for fuel in Maarat al-Naasan, a village in the Idlib province, according to the Syrian Observatory for Human Rights.

Another 23 civilians, including five women, were killed after strikes on a village held by Daesh in the northern Aleppo province.

Observatory head Rami Abdel Rahman told AFP four IDaesh militants were also killed in those raids on the village of Maskana, which hit a market as well.

Both tolls were likely to rise as many people were critically wounded, the Britain-based monitor said.

The Observatory relies on a network of sources on the ground to collect its information, and identifies aircraft based on their flight patterns and munitions used.

Russia began air operations in Syria on Sept. 30 with the aim of supporting the embattled regime of Syrian Bashar al-Assad.

While the Kremlin says the airstrikes target the Daesh militant group, some members of the western NATO alliance believe Russia is targeting groups opposed to Assad, including some that enjoy U.S. and Turkish support.

At least 250,000 people have been killed since the Syria conflict began in 2011, according to UN figures.