Human Rights Watch has called on Iraq's government to declare the number of detention facilities it maintains and not to hold suspects without informing their families.
In a report issued on Sunday, the New York-based group says Iraq's National Security Services runs a detention facility in Mosul. It said when granted access to the center on July 4, it was holding 427 men suspected of links to the Islamic State group.
An NNS officer said those prisoners were previously held in a house before a new prison block was built following ``pressure from Baghdad.''
It added that the NSS first denied running detention centers, but later acknowledged it.
HRW says the cells at the Mosul facility are clean and air-conditioned, but extremely overcrowded.