The raids hit several villages held by jihadists and rebels in the western countryside of Aleppo province, said the Syrian Observatory for Human Rights.

Three girls were killed in the village of Kfar Taal while four civilians, including two other children, died in separate strikes that hit other villages in the area, said the Britain-based monitor.

Idlib and parts of Aleppo, Hama and Latakia provinces, are dominated by the Hayat Tahrir al-Sham, a group dominated by Syria's former Al-Qaeda affiliate.

The northwestern region has come under mounting bombardment in recent weeks that displaced tens of thousands of people.

A ceasefire arranged by Syrian regime ally Russia and rebel backer Turkey this month was supposed to protect the area from further attacks.

But the Damascus government last week pressed a deadly offensive, reaching within seven kilometres of a key town in southern Idlib it seeks to capture from jihadists.

Russian and regime warplanes also continued to pummel the area, killing scores of civilians, according to the Observatory which relies on a network of sources inside Syria for its reports.

On Thursday, Russia denied launching any combat operations in the region since the start of a ceasefire which it said took effect on January 9, a date disputed by Turkey which says the truce began on Sunday.

The Syrian government, which now controls more than 70 percent of the country, has vowed to take back Idlib, which is home to some three million people.

Syria's war has killed more than 380,000 people and displaced more than half the country's population since starting in 2011 with the brutal repression of anti-government protests.