Story highlights Multiple airstrikes kill dozens and wound hundreds, aid groups say

Activist: "Dead human bodies were just left on the sidewalk"

Syria has been locked in a civil war since 2011

(CNN) Airstrikes from Syrian government forces hit the rebel-held town of Douma on Sunday, killing as many as 82 people and wounding hundreds, according to the Syrian Observatory for Human Rights and aid groups.

Graphic video purporting to show the immediate aftermath of the blast depicted massive plumes of smoke, bodies strewn on the street, and people frantically running for their lives.

The video was posted on a social media website on Sunday.

At least 250 people were wounded in the attack, conducted by President Bashar al-Assad's regime forces, activists say.

"In some places there was not enough capabilities to transfer the victims. It was very painful to see dead human bodies just left on the sidewalk," said Abdullah al-Shami, a media activist, speaking to CNN via Skype. "Scores of injured were bleeding while waiting their turn to get treatment."

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