Isis militants using methamphetamine to help them stay alert, US colonel says

Belgian special forces soldiers with a guided-missile launcher, a few kilometres from the front line, in the village of Abu Ghaddur, east of Tal Afar, Iraq. Photo / AP

As Isis (Islamic State) is driven out of Iraq and Syria, militants in the last throes of battle are turning to P in desperation.

Isis's self-proclaimed "caliphate" effectively collapsed in July when Iraqi security forces reclaimed its previous stronghold Mosul.

US Army Colonel Ryan Dillon says there is increasing evidence of Isis fighters using methamphetamine to help them stay alert during fighting.

"There were several Isis fighters that had track marks on them from taking something intravenously and that was assessed to be methamphetamine," the Combined Joint Task Force-Operation Inherent Resolve spokesman told AAP from the Middle East.

Among the short-term effects of methamphetamine are increased confidence, alertness and energy.

Another new Isis tactic he outlined was stationing children 24 hours a day outside their factories which are producing car bombs in order to ward off air strikes.

At the weekend, Iraqi security forces backed by a US-led coalition launched a new offensive to take back the city of Tal Afar.

Colonel Dillon expects the Tal Afar offensive to be slightly easier than the one to reclaim Mosul which took nine months.

Tal Afar is 80km west of Mosul, and an estimated 2000 militants remain in the city.

Australia has 780 Australian defence personnel deployed to the Middle East in the fight against Isis. Australia's contribution covers training Iraqi security forces, special operations and air strikes.

- AAP