IS can make chemical weapons, says CIA chief

CIA director John Brennan has said that Islamic State group (IS) militants have used chemical weapons and have the capability to make small quantities of chlorine and mustard gas, the American CBS News network reported Thursday.

"We have a number of instances where ISIL has used chemical munitions on the battlefield," Brennan told CBS News using an acronym for IS.

The news network released excerpts of an interview with Brennan that is to air in full on the "60 Minutes" programme on Sunday.

Brennan added that the CIA believes that IS has the ability to make small amounts of mustard or chlorine gas for weapons.

There are reports that IS "has access to chemical precursors and munitions that they can use," Brennan said.

Brennan also warned of the possibility that IS could seek to export the weapons to the West for financial gain.

"I think there's always the potential for that. This is why it's so important to cut off the various transportation routes and smuggling routes that they have used," he said.

When asked if there were "American assets on the ground" searching for possible chemical weapons caches or labs, Brennan replied: "US intelligence is actively involved in being a part of the efforts to destroy ISIL and to get as much insight into what they have on the ground inside of Syria and Iraq."

The release of the excerpts of Brennan's interview comes two days after similar comments from spy chief James Clapper before a congressional committee.

"ISIL has also used toxic chemicals in Iraq and Syria, including the blister agent sulfur mustard," Clapper, the director of national intelligence, told American lawmakers on Tuesday.

He said it was the first time an extremist group had produced and used a chemical warfare agent in an attack since Japan's Aum Supreme Truth cult carried out a deadly sarin attack during rush hour in the Tokyo subway in 1995.

Last year, officials in the autonomous Iraqi region of Kurdistan said blood tests had shown that IS fighters used mustard agent in an attack on Kurdish Peshmerga forces in August.

Thirty-five Peshmerga fighters were exposed and some taken abroad for treatment, officials said.