The Turkmen Mountain and Jabal al-Akrad areas plus rural parts of Idlib province were hit said the source, speaking on condition of anonymity.

Regime forces shelled Isapinari, Kelez and Yamadi villages of the pre-dominantly Turkmen region. Airstrikes also hit Al-Tuffahiyah in Jabal al-Akrad, Jisr al-Shughur district and Bdamah village in Idlib, killing an eight-year-old girl and injuring at least 10 people.

Clashes are ongoing, the source said and added five regime soldiers were also killed.

Syria has been locked in a vicious civil war since early 2011 when the Bashar al-Assad regime cracked down on pro-democracy protests -- which erupted as part of the "Arab Spring" uprisings -- with unexpected ferocity.

Since then, more than a quarter of a million people have been killed and more than 10 million displaced across the war-torn country, according to the UN.

The Syrian Center for Policy Research, however, put the death toll from the six-year conflict at more than 470,000 people.