Baghdad: Iraqi officials say Daesh militants used chlorine gas during fighting with Iraqi security forces and Shiite militiamen last month north of Baghdad.

The use of chlorine gas as a weapon adds a new concern to the turmoil in the country.

A senior security official, a local official from the town of Duluiya and an official from the town of Balad say Daesh used bombs with chlorine-filled cylinders during September clashes.

They said on Friday that about 40 troops and militiamen were slightly affected by the chlorine and showed symptoms consistent with chlorine poisoning, such as difficulty in breathing and coughing. They were treated in hospital and quickly recovered.

The three spoke on condition of anonymity because they were not authorised to speak to media.

Meanwhile, officials at the US military’s Central Command said on Thursday that Iraqi forces are months away from being able to start waging any kind of sustained ground offensive against Daesh and any similar effort in Syria will take longer.

In Iraq, the timing will depend on a host of factors, some out of the military’s control — from Iraqi politics to the weather. Iraqi forces also must be trained, armed and ready before major advances, like one to retake the city of Mosul, which fell to Daesh in June.

“It’s not imminent. But we don’t see that that’s a years-long effort to get them to a place to where they can be able to go on a sustained counter-offensive,” a military official said, instead describing it as a “months-long” endeavour.

The officials, briefing a group of reporters, said the priority in Iraq was halting the Daesh’s advance but acknowledged Iraq’s western Anbar province was contested, despite US-led air strikes.

Iraq’s main military divisions in Anbar — the seventh, eighth, ninth, tenth and twelfth — have been badly damaged. At least 6,000 Iraqi soldiers were killed through June and double that number have deserted, say medical and diplomatic sources.

Asked about whether US military advisers in Iraq might head to Anbar, the first official acknowledged discussions were underway broadly about efforts to enable the Iraqis “as far forward as we can” but did not disclose details. The official said talks were also underway with coalition partners about where their advisers might be placed.