Members of the Syrian opposition to President Bashar al-Assad are accusing government forces of using chemical weapons in an attack that reports are saying may have killed as many as 1,300 people outside of Damascus, according to Reuters.

The Syrian government has denied using chemical weapons in the attack while Western nations are calling for United Nations chemical weapons investigators to head to the scene to verify what happened. Pictures coming out of the area show dozens of dead bodies with no visible injuries, according to Reuters.

"Today's crimes are...not the first time the regime has used chemical weapons," George Sabra, one of the leaders of the opposition of al-Assad, said in a news conference. "But they constitute a turning point in the regime's operations. This time it was for annihilation rather than terror."

After the attacks tweets and amateur video were released showing doctors and nurses attempting to revive men, women and children with blue lips and pink spots on their skin. There are also videos that show people vomiting and convulsing, according to Time.

Many of the videos were collected by weapons expert and blogger Brown Moses and placed on YouTube. They can be seen at this link but we must warn you that they are very graphic and contain nudity as well as people dying. 

Time also is reporting that doctors in the area administered 25,000 injections of atropine, a drug used to treat nerve gas poisoning.

"The disaster is huge, we are out of all kind of medicines, we have used all our stocks from cortisone and atropine," a doctor in the area said in a YouTube video. 

Ralf Trapp, an expert on chemical and biological weapons, spoke with Time and said that while the footage that has been released appears to be from chemical weapons the U.N. team needs to get to the scene as quickly as possible to verify the cause.

"[These videos] appear to show a lot of victims, people are vomiting, they have breathing problems, and there are significant dead," Trapp said. "It all looks like it could be an attack with a chemical warfare agent, but it's impossible to rule out other possible causes."

Abu Nidal, an activist working in Syria, told Reuters that many of the people who died in the attack were first responders trying to help the injured.

"We believe there was a group of initial responders who died or were wounded, because when we went in later, we saw men collapsed on staircases or inside doorways and it looks like they were trying to go in to help the wounded and then were hurt themselves," Nidal said. "At first none of us knew there were chemical agents because it seemed like just another night of air strikes, and no one was anticipating chemical weapons use, especially with U.N. monitors in town."

If it is confirmed that chemical weapons were used in the attacks the timing seems to be very strange. Al-Assad's government had fought against allowing U.N. weapons inspectors into the country for months; conducting the largest scale chemical weapons attack the world has seen since Saddam Hussein used chemical weapons against the Kurds in the 1980's three days after investigators landed in Damascus seems odd, according to Time.

"It would be very peculiar if it was the government to do this at the exact moment the international inspectors come into the country," Rold Ekeus, a former U.N. weapons inspector, told Reuters. "At the least, it wouldn't be very clever."

If confirmed the attack may force the United States to intervene in a manner that they have avoided thus far. One year ago President Barack Obama had warned Syria that using chemical weapons would be crossing a "red line" that would force the United States into taking action against al-Assad, according to Fox News.

U.S. Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, wrote a letter to Rep. Eliot Engel, D-N.Y., explaining how complicated the situation in Syria is and why the United States has avoided involvement so far. The letter was written on Aug. 19 so Dempsey's viewpoint does not take the most recent attack into consideration, according to Fox News.

"It is a deeply rooted, long-term conflict among multiple factions, and violent struggles for power will continue after Assad's rule ends," Dempsey wrote. "We should evaluate the effectiveness of limited military options in this context."