Updated

U.S. intelligence officials say they have authenticated at least 13 videos that show the aftermath of an alleged Syrian gas attack, in which men and children are seen struggling for breath and convulsing, according to a government official.

The Washington Post reports that the graphic videos, made public on YouTube and other online media outlets, are among as many as 100 available that claim to show victims of an attack near Damascus on Aug. 21.

The Central Intelligence Agency has confirmed these 13 videos as authentic, the government official told the Washington Post.

The videos do not make clear who used the chemical weapons, however the videos were filmed by Syrians sympathetic to the rebels fighting against Syria President Bashar al-Assad and his regime.

The videos were shown to senators on Thursday at the request of Sen. Dianne Feinstein, D-Calif., chair of the Senate Intelligence Committee during a classified briefing.

On Saturday, Sen. Feinstein posted the videos to her website, accompanied by a disclaimer.

The Obama administration has said that it has confirmed that the Assad regime is responsible for the Aug. 21 chemical attack.

Click for more at The Washington Post.