Syria chlorine gas attack alleged by activists
Activists in Syria have published what they say is evidence of a chlorine gas attack by government forces.
Footage posted online, which cannot be verified, shows medics trying to revive four young men suffering what appear to be symptoms of poisoning.
A voice off-screen says the location is Harasta, just outside the capital Damascus.
Use of chlorine as a weapon of war is banned and Syria committed to declaring and giving up its stocks last year.
The face of one of the men in the video appeared to be covered in vomit, as he shook and moaned while doctors treated him.
It is the fourth chemical weapons attack the opposition has alleged this month.
Four days ago, activists said the Syrian government carried out another alleged chlorine attack north of the city of Hama. The Syrian government blamed the opposition.
Opposition activists have also posted online unverified photographs and video of what they said was an improvised chlorine "barrel" bomb dropped from helicopters on the the rebel-held village of Kfar Zeita during attacks on Friday and Saturday last week.
A UN inquiry found in December that the nerve agent sarin had likely been used in several locations around Syria, including three areas of the Ghouta agricultural belt around the capital, where hundreds of people were killed in August.
As with the recent attacks, both sides blamed each other, but the US and other Western countries concluded the government of President Bashar al-Assad was responsible.
After they threatened punitive military strikes, Mr Assad agreed to the complete destruction or removal of Syria's stockpile of chemical weapons.
The Syrian government has since failed to meet the 5 February deadline to move its 1,300 tonnes of declared chemical warfare agents and precursors out of the country, and a subsequent 13 April deadline.
The chemicals are supposed to be completely destroyed - a process that takes at least a month - by 30 June, and the Organisation for the Prohibition of Chemical Weapons (OPCW) recently warned that that deadline too will be missed unless Syria significantly speeds up delivery.
Syria's 13th consignment of chemicals was shipped out of Latakia port on Monday, taking the amount removed so far to 65% of declared stockpiles.
The Syrian Observatory for Human Rights estimates that more than 150,000 people, a third of them civilians, have been killed in the civil war, which began as peaceful protests against President Assad's rule. The UN stopped counting at 100,000 as it said it was no longer possible to ensure the reliability of the data.
A further 2.5 million people are thought to have fled Syria since the start of the conflict, with an estimated 6.5 million people displaced inside the country.