Moscow-backed government forces have upped their deadly bombardment of the jihadist-dominated region in recent weeks, chipping at its southern edge and causing tens of thousands to flee their homes.

Seven of those killed were members of the same family in the town of Sarmeen, though it was not immediately clear whether the government or Russians carried out that strike.

A regime air strike also killed a child in the town of Binnish, and a Russian raid took the life of a woman in the town of Atareb, the Observatory said.

In Sarmeen, an AFP correspondent saw a man weeping as rescue workers pulled two bodies from a crumpled two-storey building.

They belonged to his nine-year-old daughter and a 13-year-old son.

The Observatory says it relies on sources inside Syria for its information, and determines who carries out air strikes according to flight patterns as well as aircraft and ammunition involved.

Syria's civil war has killed more than 380,000 people since it started in 2011 with the brutal repression of anti-government protests.