Activists and rebel fighters accused Syrian President Bashar al-Assad's forces of killing hundreds of civilians — including many women and children — in chemical weapons attacks on the outskirts of Damascus, Wednesday.
Unverified video clips now circulating on the internet through social media reportedy show the graphic and disturbing aftermath of the attacks, including "children choking and vomiting" and adults writhing in agony.
According to activists, rockets with toxic agents were launched at the suburbs of the Ghouta region as part of an major attack on rebel forces. The Syrian army, however, described the accusations as grave and accused the opposition of fabricating claims to divert attention from the huge losses rebel forces have suffered.
"Many of the casualties are women and children. They arrived with their pupils dilated, cold limbs and foam in their mouths. The doctors say these are typical symptoms of nerve gas victims," said Susan Ahmad, a nurse at a field hospital in Douma.
Although it is still not clear how many died in the alleged attacks so far, but if confirmed this could be by far the worst use of poison gas during Syria's long and deadly civil war.
The alleged Syrian chemical attack is also not the first one the world has seen.
Here's a list of numerous infamous chemical attacks celebrities across the globe in recent history:
World War I came to be known as the "chemists' war" for its use of deadly gases in combat.
The first major use of a chemical weapon in modern warfare came in the Second Battle of Ypres when the German army released thousands of yellow-green chlorine gas cylinders across the battlefield. The gas was used as a choking gas and caused fluid to build up in victims' lungs to kill hundreds of French soldiers.
"We remember the awful sights in the hospital, the gas patients who, suffocating, cough up their burnt lungs in clots," Paul Baumer recalled in All Quiet on the Western Front Better. "Better to take your chances in the open rather than stay in the hollows and low vapors where the vapors settle."
There were an estimated 100,000 casualties due to gas attacks in World War I, leading the League of Nations to draft a document that prohibited chemical and biological warfare.
The firebombing of Tokyo in the final months of World War II saw the use of a new chemical agent — napalm. The sticky, gel-like substance was invented at Harvard University and was used to deplete the air of oxygen.
In a single U.S. firebomb raid, 330 American B-29s rained incendiary bombs on Tokyo, killing an estimated 100,000 people, burning a quarter of the city to the ground, and leaving a million homeless.
Temperatures in some parts of Tokyo reached 1,800 degrees Fahrenheit in some places.
Developed in the 1940s, the chemical weapon Agent Orange was used by the U.S. Army to spray local landscapes and destroy the opposition's food and cover. The herbicide, however, posed serious dangers for both Vietnamese civilians and U.S. soldiers.
According to the Aspen Institute, a toxic ingredient in Agent Orange called dioxin can remain in the human body for over a decade.
Those exposed to the chemical continue to suffer from its effects ore than half a century after the Vietnam War. The National Academy of Sciences has found potential links between Agent Orange and some cases of diabetes and cancer in veterans and some birth defects in children of veterans.
The Halabja poison gas attack, also known as Bloody Friday, took place on March 16, 1988 during the end of the Iran-Iraq war. Analysts say the Iraqi military used a cocktail of chemical agents including deadly mustard gas and nerve agents including sarin, tabun, and VX.
Nerve agents are one of the most lethal and quickest-acting category of chemical weapons, with the potential to kill a person in mere minutes.
Former Iraqi dictator Saddam Hussein ordered the bombing of Kurdish town of Halabja during his attack on Iraqi Kurds killing thousands of people on the spot, and injuring more than 10,000.
"It was life frozen," said Iranian photo-journalist Kaveh Golestan shortly after the attack. "Life had stopped, like watching a film and suddenly it hangs on one frame. It was a new kind of death to me. You went into a room, a kitchen and you saw a body of a woman holding a knife where she had been cutting a carrot."
Commonly known as the Subway Sarin incident by the Japanese media, the deadly domestic terrorism attack took place on March 20, 1995 when a religious cult leaked lethal gas into Tokyo's subway system during rush hour.
Five members of the religious Aum Shinrikyo doomsday cult boarded subway trains around 8 a.m., each carrying 2-3 bags of liquid sarin, tightly enclosed in plastic and wrapped in newspapers. They then dropped their packages onto the floor and used the sharp end of their umbrellas to puncture holes through the plastic and release the toxic sarin gas.
The sarin gas, estimated to be 500 times more potent than cyanide gas, killed 13 train passengers and injured more than 5,500 in the attack. Many victims still suffer from the effects of the toxic gas, including paralysis, blindness, and cognitive damage.