On 29 November 1981, Iran began Operation Tariq al-Qods with three army brigades and seven Revolutionary Guard brigades. The Iraqis failed to properly patrol their occupied areas, and the Iranians constructed a road through the unguarded sand dunes, launching their attack from the Iraqi rear. The town of Bostan was retaken from Iraqi divisions by 7 December. By this time the Iraqi Army was experiencing serious morale problems, compounded by the fact that Operation Tariq al-Qods marked the first use of Iranian "human wave" tactics, where the Revolutionary Guard light infantry repeatedly charged at Iraqi positions, oftentimes without the support of armour or air power. The fall of Bostan exacerbated the Iraqis' logistical problems, forcing them to use a roundabout route from Ahvaz to the south to resupply their troops. 6,000 Iranians and over 2,000 Iraqis were killed in the operation.