Fuel truck explosion kills dozens in Syrian border town

At least 43 people were killed Saturday when a car bomb went off in a busy market in a rebel-held Syrian town along the Turkish border, activists and rescue workers said.

The explosion ripped through the central market in the town of Azaz in the northern province of Aleppo, damaging a government building and local court house as well.

Rami Abdurrahman, the head of the Syrian Observatory for Human Rights monitoring group, said those killed included six opposition fighters. He said the explosion was caused by a rigged water or fuel tanker, which explains the large blast and high death toll.

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Other activist groups, including the Azaz Media Centre, put the death toll at 50, adding that search and rescue operations continued for at least two hours after the explosion. The Observatory said the explosion took place near the local court house operated by rebel groups.

Inunsourcedcomments, Turkey's privately-ownedDogannews agency said a car bomb planted by the Islamic State inIraq and Syria (ISIS) was responsible. There was no immediate claim of responsibility from the militant group.

Turkey's state-run Anadolu news agency cited a doctor in Azaz as saying at least 60 people had been killed and more than 50 wounded. An Azaz resident who went to the local hospital told Reuters he had counted around 30 bodies laid out.

Aleppo province-based media activist Baha al-Halabi, who gathered information from people in Azaz, said witnesses said there were many unidentified bodies because of the strength of the explosion.

Images shared online showed a huge plume of black smoke rising above the chaotic market and sounds of gunfire echoing in the background as onlookers gathered around the site. Bodies were strewn on the ground as a father ran away from the scene hugging his child.

Syria's nearly six-year war has create a patchwork of areas of control across the country, and Azaz is a major stronghold of the Turkish-backed Free Syrian Army (FSA).

Many rebels and civilians who were pushed out of Aleppo city during a massive government offensive late last year resettled in Azaz.

To the west of Azaz, Syrian Kurdish forces have control of a swath of land, and they have often tried to advance toward the town, causing friction with Turkish troops and allied Syrian opposition fighters.

To the east, opposition fighters backed by Turkey have been pushing back ISISextremists, gaining territory and advancing on the ISIS-stronghold town of al-Bab, further east.