WARNING GRAPHIC CONTENT: First moments a suicide attack hit Syrian border-town

Update: Up to 36 people were killed, dozens others injured as a suicide blast rocked a Syrian border-town with Turkey.

Social media activists confirmed that most of the killed in Atmeh crossing border are militants fighting under the anti-ISIS, Turkish-backed Operation Euphrates Shield, including Ahrar al-Sham military commander Hisham Khalifah, and head of Supreme Judiciary Authority in Aleppo, Khalid al-Sayyed.

ISIS claimed responsibility for the attack via an official statement released on its social media account, Aamaq Agency.

Pro-rebel activists reported the attack was carried by either an exclusive vest of a booby-trapped handbag, ruling out the narrative circulated on social media about a VBIED explosion.