"Regime forces directly targeted residential areas of the city of Idlib," said the Syrian Observatory for Human Rights, adding that industrial areas were also hit, as well as "residential areas in the town of Sarmin" nearby.
Six civilians, "including two children and a woman", were killed in Idlib and Sarmin, while 25 others were wounded in the strikes in various areas of Idlib province, added the Britain-based Observatory.
Government forces fired "more than 35 missiles" during the bombardment, it added.
Hayat Tahrir al-Sham (HTS), led by Al-Qaeda's former Syria branch, controls swathes of Idlib province and parts of the neighbouring Aleppo, Hama and Latakia provinces.
HTS is considered a terrorist group by Damascus, as well as by the United States and the European Union.
Parts of the rebel bastion have seen fierce fighting in recent days, according to the Observatory.
On Friday, it said 11 pro-government forces and five HTS fighters had been killed after the jihadists launched an attack in neighbouring Aleppo province a day earlier.
Late last month, Syrian government bombardment killed nine civilians including six children as they harvested olives in Idlib province, reported the Observatory, which relies on a network of sources inside Syria.
Civil war erupted in Syria after President Bashar al-Assad crushed peaceful anti-government protests in 2011.
The conflict has killed more than half a million people and displaced millions after spiralling into a devastating war involving foreign armies, militias and jihadists.
A ceasefire brokered by Russia and Turkey was declared in Idlib after a government offensive in March 2020, but it has been repeatedly violated.
