Videos released by Syrian activists shows aftermath of alleged chemical attack in Syria

— -- Video released by media activists in Syria shows the moment a hospital treating victims of a suspected chemical attack is hit by airstrikes.

The video, taken by local activist Fadi al-Halabi inside a hospital in the northern Syria town of Khan Sheikhoun, was meant to report on the victims of the suspected chemical attack.

While filming, the activists mention in Arabic that they hear warplanes flying overhead before an explosion throws the camera out of focus. After the blasts, the men filmed a short video informing their followers that they were alive and safe.

Another video, released by prominent Syrian journalist Hadi al-Abdallah, shows the purported blast site of the chemical attack. Al-Abdallah wears a face mask over his mouth and nose as they walk through the site, which appears to be in ruins. He also tours a hospital in Khan Sheikhoun that was allegedly hit by a double-tap airstrike.

Hadi also spoke to White Helmets, who told him that their headquarters was targeted by airstrikes.

The alleged attack, in the northern Syria town of Khan Sheikhoun, killed at least 72 civilians, including 20 children, the Syrian Observatory for Human Rights reported.

Gas that caused victims to choke and faint appeared to be used in the attack, according to the Observatory, a U.K.-based monitoring group, medics Syria Civil Defense and residents. Several residents were still asleep when the attack happened early Tuesday, Abdullah al-Hussein, a Syria Civil Defense volunteer who was at the scene, told ABC News in a voice recording in Arabic.

Airstrikes later hit a hospital where some of the victims were being treated. Abdullah said he saw more than 100 injured people and at least 20 bodies of children, women and men at one of the hospitals treating victims.

White House press secretary Sean Spicer said Tuesday that the attack was a "consequence of the past administration's weakness and irresolution," adding that former President Barack Obama "did nothing" after promising in 2012 to establish a "red line" on the use of chemical weapons.