(CNN) ISIS has claimed responsibility for a horrific day of carnage that devastated southern Syria on Wednesday.

At least 166 people were killed in a suicide bombing and attacks that took place in the southern province of Suwayda, the United Nations Office for the Coordination of Humanitarian Affairs in Syria tweeted.

ISIS said it was responsible, in a statement posted on the ISIS-affiliated Telegram channel. ISIS said "soldiers of the caliphate" first attacked security positions and government targets in Suwayda city. After the attackers ran out of ammunition, they detonated their explosive vests, ISIS said.

One suicide bombing at a vegetable market killed 38 people, the state-run Ikhbariya TV reported.

State TV showed footage of charred bodies, damaged vehicles and a blown-up street market.

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