Regime artillery fire killed four civilians including a child on Tuesday in Idlib city, Syria's last major rebel bastion, a war monitor said.
It was the first such deadly bombing on the north-west Syrian city for about 10 months, the Syrian Observatory for Human Rights said from Britain.
Shelling by pro-Damascus fighters killed a woman in a residential neighbourhood, while a top university official and his son and another man died when artillery fire hit near a swimming pool on the edge of the provincial capital.
Rescue workers and civilians carried the body of the young woman from her family home to an ambulance, as alarmed onlookers fled the scene fearing more shelling, AFP reported.
The Idlib region is home to nearly three million people, two thirds of them displaced from other parts of the country during the decade-long civil war.
The opposition stronghold is made up of less than half of Idlib province, including the city, and slivers of adjacent provinces.
It is dominated by Syria's former Al Qaeda affiliate, but rebels and other militants are also present.
A ceasefire deal brokered by regime ally Russia and rebel backer Turkey has largely protected the region from a new government campaign since March 2020.
But regime forces have over recent months increased their shelling on the southern edges of the bastion.
Syrian President Bashar Al Assad in July took the oath of office for a new term, vowing to make "liberating those parts of the homeland that still need to be" one of his top priorities.
Syria's war has killed about 500,000 people since starting in 2011 with a brutal crackdown on anti-government protests.