The US-led coalition air strikes against Islamic State (IS) militant targets in Iraq are "peanuts" according to Iraq's former national security adviser, Dr Mowaffak al-Rubaie.

Describing the fight against IS as a "war of attrition", Dr al-Rubaie called for an intensification of air strikes, help with the retraining of Iraqi security forces and a greater sharing of intelligence information.

More than 400 air strikes have been carried out in Iraq since 8 August.