A camera pans slowly over a row of children partly under a sheet, their eyes closed, their skin looking sallow. A man behind them, crazy with anger, shouts, "Stop lying to us! Stop lying! Where did all these children go? Where is this regime ... that is killing us?
"Chemical weapons," he screams, holding his head. "We were hit with chemical weapons!"
Inside a medical area, it's chaos. Footage shows people carrying limp bodies, some haphazardly covered in sheets, others splayed, nearly nude, on the floor. A man is on his back, staring blankly upward, his chest convulsing violently. Others hold tissues to their mouth, appearing to gag.
These were some of the videos posted online that opposition activists in Syria say show that the government has used chemical weapons in the countryside outside its capital Damascus.
The allegations come as a U.N. group arrived in Syria this week to determine whether either side in the conflict is using chemical weapons.
Hours after the videos were reported on across international news, U.N. Secretary-General Ban Ki-moon's spokesperson issued a statement saying that he was "shocked" by the reports. The U.N. mission is "fully engaged in the investigation process" and the team, which began work Monday, "is in discussions" with the Syrian government," the statement read. "The Secretary-General reiterates that any use of chemical weapons by any side under any circumstances would violate international humanitarian law."
Syrian activists have been pushing since March 2011 to oust President Bashar al-Assad.
CNN could not immediately verify where or when the videos were recorded, and could not authenticate the number killed or injured.
The war has killed more than 100,000 people and displaced millions, according to the United Nations.
There have been repeated allegations that chemical weapons were being used during the course of the conflict.
On Wednesday Al-Assad's government denied the allegations, calling them "completely baseless" on Syria's state-run media.
Initially Syrian opposition groups claimed that hundreds were killed Wednesday, but as the day wore on, the number went up -- more than 1,300 people, according to the opposition Local Coordination Committees and the Syrian National Council. The council is an umbrella group of anti-regime activists.
A senior Obama administration official said the United States had no official confirmation that chemical weapons were used in recent attacks in Syria.
"If true, it would be further evidence of unconscionable brutality by a desperate man and a desperate regime," the official said.
The White House released a statement about the allegations saying that the U.S. is "deeply concerned by reports" that chemical weapons were used" and that officials are "working urgently to gather additional information."
"The United States strongly condemns any and all use of chemical weapons," it reads. "Those responsible for the use of chemical weapons must be held accountable. Today, we are formally requesting that the United Nations urgently investigate this new allegation."
The U.S. urged that the U.N. team be given "immediate access to witnesses and affected individuals, and have the ability to examine and collect physical evidence without any interference or manipulation from the Syrian government.
"If the Syrian government has nothing to hide and is truly committed to an impartial and credible investigation of chemical weapons use in Syria, it will facilitate the UN team's immediate and unfettered access to this site."
"We are aware of the reports (of chemical weapons), and we are trying to find out more," U.N. spokesman Martin Nesirky said Wednesday.
The alleged attacks took place in eastern and western Ghouta, rebel strongholds that the regime has been desperately trying to take back for more than a year. They don't want rebels pushing into the capital.
"The inspectors will not come," said a resident who didn't want his name used. "If they wanted to come, they would have come a long time ago.
"The Assad regime determines where the inspectors go, and they will not let them go there. There is already a siege around eastern Ghouta from the Assad regime."
Russian officials, meanwhile, dismissed the claims of chemical weapons as a "provocation planned in advance," Russian Foreign Ministry spokesman Alexander Lukashevich told Interfax news agency.
"The fact that agenda-driven regional mass media have begun an aggressive attack at once, as if on command, laying all the responsibility on the government, draws attention," the reports quotes Lukashevich saying in a statement Wednesday.
"The fact that the criminal action near Damascus was carried out just when the mission of UN experts to investigate the statements on possible chemical weapons use there has successfully begun its work in Syria points to this," according to the report.