Both sides in the Syrian war have been accused of killing civilians on Friday, as a three-day old truce to coincide with the Muslim holiday of Eid al-Fitr collapsed.
Pictures uploaded to social media purported to show the aftermath of a bombardment on the town of Darkush near the Turkish border.
People lay dead and were carried away on stretchers. Families had come come to the riverside area to enjoy the Eid weekend, reports say.
A monitoring group claimed 23 people were killed as the Syrian army attacked the rebel-held town.
The dead included ten women and two children, serious injuries meaning the toll is likely to rise according to the foreign-based Syrian Observatory for Human Rights.
Reuters said it was confident the events portrayed were genuine, after the images were analysed by its social media team.
Meanwhile rebel-held parts of Aleppo are said to have been almost completely encircled by government forces.
Unverified video is said to show a government-led offensive north of the city, as soldiers fire at opposition outposts.
The Syrian Observatory for Human Rights says rebel attacks on government-held districts killed at least 18 civilians including four children, injuring over 120.
The government advance put its forces within striking distance of a major supply route for the rebels, effectively putting opposition-held areas under siege.
Away from the carnage – state TV broadcast images it said showed President al-Assad and his family in Homs visiting the homes of Syrian soldiers who were wounded during the war.
Syria’s president, accused of being responsible for some of the most barbarous attacks on his country’s civilians, took part in prayers for Eid.