Iraqi Kurdish President Masoud Barzani's chief of staff said on Sunday that the number of Islamic State (IS) militants has reached at least 200,000.
Speaking with UK newspaper The Independent, Fuad Hussein said that the number is "seven or eight times bigger than" estimates of foreign intelligence, especially the CIA.
"I am talking about hundreds of thousands of fighters because they are able to mobilise Arab young men in the territory they have taken," the newspaper quoted him as saying.
Hussein argued that IS governs a "third of Iraq and a third of Syria," areas with a population of 10-12 million and 250,000 square km in terms of area.
"In Kurdistan last month they were attacking in seven different places as well as in Ramadi [capital of Anbar province, west of Baghdad] and Jalawla [an Arab-Kurdish town close to the Iranian border]. It is impossible to talk of 20,000 men or so," he said.
Moreover, he referred to how IS has quickly learned how to use captured US weaponry, tanks and other heavy equipment, which reflects how well trained the group is.
"For instance, they have the best snipers, but to be a good sniper you need not only training on how to shoot, but discipline in staying put for up to five hours so you can hit your target," he stressed.
An explanation for this, he contends, is that IS's ranks contain many former Iraqi and Syrian soldiers whose skills the militant group have utilised.
CIA spokesman Ryan Trapani said in a statement in September that IS numbers range between 20,000 and 31,500 militants across Iraq and Syria.
Trapani pointed out that the raised figures are based on a boost in stronger recruitment since June after military success as well as the declaration of an Islamic caliphate, greater military activity and additional intelligence