Iraq has so far received 5,046 of the around 7,000 IS detainees previously held by Syrian Kurdish fighters, whom the US military began transferring from Syria last month.

The detainees who have arrived in Iraq include 3,245 Syrians, 271 Iraqis and another 610 detainees from other Arab countries including Egypt, Tunisia, Morocco and Saudi Arabia.

They also include more than 900 foreigners from Europe, Asia and even Australia.

The largest group of Europeans is from Germany, with 27 detainees.

There are also 10 suspects from the Netherlands, nine from the United Kingdom, 13 from Australia, four from Sweden and three from France, among others.

The foreigners also include more than 130 Russians and 160 suspects from Turkey.

Many prisons in Iraq are already packed with IS suspects, and courts have handed down hundreds of death sentences and life terms to those convicted of terrorism offences, including many foreign fighters.

Earlier this month, Iraq's judiciary said it had begun investigations into detainees transferred from Syria.

In 2014, IS swept across Syria and Iraq, committing massacres and forcing women and girls into sexual slavery.

Backed by US-led forces, Iraq proclaimed the defeat of IS in the country in 2017, and the Kurdish-led Syrian Democratic Forces (SDF) ultimately beat back the group in Syria two years later.

The SDF went on to jail thousands of suspected jihadists and detain tens of thousands of their relatives in camps.

Last month, the United States said the purpose of its alliance with Kurdish forces in Syria had largely expired, as Damascus pressed an offensive to take back territory long held by the SDF.