British experts say Sarin-like agent used in Syria chemical attack

Samples taken from the alleged chemical weapons attack in Syria last week tested positive for the nerve agent Sarin or a similar substance, the British delegation at the world's chemical weapons watchdog said on Thursday.

"UK scientists have analysed samples taken from Khan Sheikhun. These have tested positive for the nerve agent Sarin, or a Sarin-like substance," the delegation said during a special session at the Organisation for the Prohibition of Chemical Weapons in The Hague.

Earlier testing by Turkish authorities had also said the chemical used on April 4 was sarin.

The OPCW mission will determine whether chemical weapons were used, but is not mandated to assign blame.

Its findings, expected in three to four weeks, will be passed to a joint UN-OPCW investigation tasked with identifying individuals or institutions responsible for using chemical weapons.

Russia agrees to support investigation

Turkish President Tayyip Erdogan and Russian President Vladimir Putin agreed on Thursday to support the investigation by the Organisation for the Prohibition of Chemical Weapons into the chemical weapons attack in Syria last week, Turkish presidential sources said.

In a phone call, Erdogan stressed to his Russian counterpart that the use of chemical weapons was a crime against humanity, they said.

International investigators have concluded that Sarin, chlorine and sulphur mustard gas have been used in Syria's six-year-old conflict, with government forces using chlorine and Islamic State militants using sulphur mustard.

Last week's poison gas attack in Khan Sheikhun, Idlib, was the most lethal since a Sarin attack in August 2013 killed hundreds in a rebel-controlled suburb of the capital Damascus.