The latest strikes in the fiercest wave of regime bombardment on a jihadist enclave in northwestern Syria killed at least 15 civilians on Wednesday, a war monitor said, despite calls to halt the attacks.
Air strikes by Russian and government warplanes, some using barrel bombs, and shelling have claimed a mounting civilian death toll over the past few weeks.
The violence, which comes despite a truce deal brokered by Moscow and Ankara in September, has caused mass displacement and heightened fears of the worst humanitarian catastrophe in Syria's eight-year conflict.
The United States and the United Nations demanded an end to the bombardment on Tuesday, as strikes by Damascus killed 27 people -- the single highest civilian death toll in the region since the regime increased its attacks in late April.
But the aerial bombardment on Wednesday did not relent against Idlib province, most of which is controlled by Hayat Tahrir al-Sham, a group dominated by former members of Al-Qaeda's Syria affiliate.
According to the Britain-based Syrian Observatory for Human Rights monitoring organisation, seven of Wednesday's victims were killed in an air raid on the village of Sarja.
A father and his three children were killed in the village of Bara and four other civilians died in strikes in the towns of Hbeit and Areen, said Observatory chief Rami Abdel Rahman.
"The bombardment by the regime and Russia continues to be intense on several areas. The Russian strikes are focused on Khan Sheikhun but have not caused any casualties for now," he said.
Syrian state news agency SANA reported one woman was killed by jihadist shelling on northern Hama.
The civilian death toll has mounted in and around Idlib in recent days, reaching more than 270 over the past month, according to the Observatory.
In villages struck by regime raids, excavators have dug new graves and civilians buried the dead stealthily at dusk to avoid being targeted by more air raids.
Despite the surge in attacks the government has not announced an all-out offensive to retake the entire jihadist enclave, a large area which is home to almost three million people.
Analysts predict that President Bashar al-Assad and his allies will continue to chip away at the area but not unleash a major assault that would create chaos on Turkey's doorstep.
The regime is likely to continue applying sustained military pressure whilst attempting to preserve the fragile truce agreement reached in Russia last year to spare the region a large-scale humanitarian disaster.
On Tuesday, Syria's UN envoy Bashar Jaafari said Damascus "will spare no effort" to end the jihadist control of Idlib, according to comments carried by SANA.
UN deputy aid chief Ursula Mueller, however, told the Security Council that a further escalation would threaten humanitarian assistance for the region's residents.
She said some 270,000 people had been displaced by the fighting in Idlib since late April.
Aid agencies have been forced to suspend their work in some areas, she said.
At least 23 medical facilities have been hit since April 28, including two medical facilities that have been attacked twice, said
David Swanson, a spokesman for the UN humanitarian office. Five health workers have died and 7 others were injured as a result, he told AFP on Wednesday.
The United States has said that "indiscriminate attacks on civilians and public infrastructure such as schools, markets and hospitals is a reckless escalation."
The conflict in Syria has killed more than 370,000 people since it started in 2011.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)