Pro-regime forces and opposition fighters exchanged fire in northwest Syria on Tuesday, killing seven civilians, said the Syrian Observatory for Human Rights, after Damascus scrapped a ceasefire.
A Friday truce was supposed to protect three million people living in the Idlib region after three months of deadly bombardment.
But extremists running the region on Saturday refused to comply with a key condition to that truce, declaring they would never withdraw from a planned buffer zone around the area.
On Monday, Damascus declared the truce over, accusing its opponents of attacking civilian areas and bombarding an air base of its ally Russia.
On Tuesday, Russian air strikes on the town of Khan Sheikhoun in Idlib province killed four civilians, the Observatory said.
In two regime-held villages in Hama province, rocket fire by extremist groups and allied opposition factions took the lives of three civilians including a child, the Britain-based monitor said.
Observatory chief Rami Abdel Rahman said however that airstrikes were not as intense as the previous day.
After the truce was scrapped on Monday, regime barrel bombs killed four civilians in the town of Morek in the northern Hama region, the Observatory said.
During the truce, air raids had stopped but land-to-land fire continued, killing one civilian on each side, according to the monitor.
Hayat Tahrir al-Sham, an extremist group led by Syria’s former Al-Qaeda affiliate, has since January controlled most of Idlib province as well as adjacent parts of the Hama, Aleppo and Latakia governorates.
Other opposition factions and extremists are also present.
A Turkish-Russian deal struck in September last year was supposed to avert a massive regime offensive on Idlib.
But that deal was never fully implemented as extremists refused to withdraw from the planned demilitarized cordon.
Instead, heightened attacks by the regime and Russia have killed 800 civilians and pushed 400,000 people from their homes since the end of April, according to the UN.
Syria’s conflict has killed more than 370,000 people and driven millions from their homes since it started with the brutal repression of anti-regime protests in 2011.