A Syrian monitor says a vehicle bomb in a town near the Turkish border has killed at least 19 people.
Rami Abdurrahman, the head of the Syrian Observatory for Human Rights monitoring group, said those killed included six opposition fighters. The explosion occurred near the rebel-held town of Azaz and authorities believe it was caused by either a rigged fuel or water tanker.
Azaz, in Aleppo province, has been a FSA stronghold since they wrestled it from "Islamic State" ("IS") control in a Turkey-backed surge several months ago. "There were so many killed, so many injured", he said.
The group said the toll was likely to rise in the attack, which was the latest in a string of bombings to hit Azaz.
There was no immediate claim of responsibility from the militant group. The Turkish state-run Anadolu news agency said 53 wounded Syrians were brought to Kilis' local hospital for treatment, including five in critical condition, transferred to Gaziantep.
In unsourced comments, Turkey's privately owned Dogan news agency said a auto bomb planted by Islamic State was responsible.
Some 50 kilometers southeast of Azaz, heavy clashes are ongoing in the town of al-Bab with Daesh terrorists since mid-December.
The town has recently been targeted by so-called Islamic State.
The latest news come amid a nationwide ceasefire in Syria, brokered by Russian Federation and Turkey, and welcomed by the UN Security Council in December 2016.
More than 310,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests.