A fuel truck has exploded in a rebel-held town near the Syrian border with Turkey, killing dozens of people, reports say.
The Syrian Observatory for Human Rights said 48 people, mostly civilians, were killed on January 7 when the tanker exploded in front of a courthouse in the northern town of Azaz.
It said around 14 rebel fighters were among the dead.
The London-based monitoring group added that dozens of people were also critically wounded in the explosion.
Footage from the scene showed huge clouds of smoke rising from the street and vehicles on fire. The fire brigade was shown battling to put out the fires with a water tanker while bulldozers cleared the street.
Azaz is a major stronghold of the Free Syrian Army, an alliance of rebel groups backed by Turkey whose fighters have pushed Islamic State (IS) militants out of the border area.
There was no immediate claim of responsibility for the attack, but rebel groups blamed the explosion on a car bomb planted by IS militants.
The blast was the latest in a string of bombings to hit Azaz. In October, at least 17 people were killed in a car bombing of a rebel checkpoint.
It was also the second major incident since a cease-fire brokered by Russia and Turkey went into force on December 30.
The cease-fire has largely held, despite sporadic violence near Syria's capital, Damascus.
A car bomb in the government-held coastal town of Jableh on January 5 that killed 10 people was the first major incident since the truce took effect.
The Syrian government blamed that attack on IS militants.
The truce in Syria is slated to be followed by peace talks in the Kazakh capital, Astana, later this month.