Syrian government officials have denied the use of chemical weapons against rebels after a video emerged reportedly showing the aftermath of an attack.

The images were apparently recorded at a medical facility near the city of Aleppo.

The video was taken in a hospital and shows men and women frothing at the mouth and twitching from the effects of the nerve agent. It was posted online just over a week ago.

The images were recorded at the medical facility in Afrin where the alleged sarin attacks by the Bashar al-Assad regime were carried out.

The British Foreign Office says it has "limited but persuasive evidence" the nerve agent sarin has been used. While the US says it believes "with some degree of varying confidence" chemical attacks have taken place.

Last month in Israel US President Barack Obama repeated his warning that if chemical weapons are used he would take action.

While the British Prime Minister David Cameron says the evidence is "serious".

"Do I think that putting boots on the ground in Syria is the right thing to do? No I don't, and I don't think we should do it. In the light of the news about the chemical weapons, we'll be stepping up those efforts, piling on that pressure, working with that opposition" he said.

The US Secretary of Defence Chuck Hagel said yesterday that they believe chemical weapons were used on a 'small scale'.