The United Nations on Wednesday condemned a deadly uptick in violence in Syria's last opposition bastion.
Najat Rochdi, senior humanitarian adviser to the UN's Syria envoy, called for "immediate de-escalation" a day after a war monitor reported that regime air strikes and artillery fire had killed 23 civilians.
Rochdi condemned "the recent intensification of hostilities in northwest Syria, in particular aerial bombardments and the reported use of barrel bombs, killing tens of civilians including women and children," her office said in a statement.
The extremist-dominated region of Idlib is supposed to be protected by a months-old ceasefire deal to prevent a broad regime offensive, but bombardment has continued.
The Britain-based Syrian Observatory for Human Rights said Tuesday about 30 were wounded, including some seriously.
An AFP correspondent said strikes continued in the area on Wednesday, and the Observatory reported that four civilians had been killed by bombardment on the area by the regime and its Russian ally.
"Despite repeated assurances that warring parties only strike legitimate military targets, attacks on health and education facilities continue," Rochdi's statement said.
The Idlib region, which is home to some three million people including many displaced by Syria's civil war, is controlled by the country's former Al-Qaeda affiliate.
The Damascus regime has repeatedly vowed to take back control of it.
Pro-regime forces launched a blistering offensive against the region in April, killing about 1,000 civilians and displacing more than 400,000 people from their homes.
Moscow announced a ceasefire in late August, but strikes and skirmishes have persisted.
Syria's war has killed over 370,000 people and displaced millions from their homes since beginning in 2011 with the brutal repression of anti-regime protests.