BAGHDAD — A uniformed guard unfastened two padlocks and tugged open a large wooden door, releasing a rush of hot, fetid, sweaty air.
Inside, in a room the size of a high school gymnasium, 505 detainees stood or sat shoulder to shoulder on cardboard boxes and stained mattress pads. Their few clothes, copies of the Koran and other belongings hung from the walls or rafters. Metal ceiling fans barely disturbed the thick air.
The stench of human confinement intensified as the guard led the way to the back of the room and down a dark, flooded hallway to the bathroom, where half-naked detainees stood barefoot amid muddy puddles, broken floor tiles and stopped-up urinals. A shower and sink were filled with human waste.
The guard dropped his cigarette butt in a puddle as detainees relieved themselves in two holes and rinsed off under a broken water pipe.
Things had improved since the morning, the detainees said. The water was flowing.
This facility, the National Police detention center in northwest Baghdad, was intended to house up to 300 inmates when it opened two years ago. Nearly 900 are now crammed inside -- an unwieldy mix of suspected insurgents, alleged criminals and apparent innocents.
Other Iraqi detention facilities have seen a similar influx since the launch of the U.S.-led security crackdown in February.
Partially treated wounds, skin diseases and grossly unsanitary conditions appear common here. So, too, is extortion by guards, say U.S. officials who serve as advisors to the Iraqi staff, but disclaim responsibility for the conditions inside.
"They're Iraqi government facilities. We work with the Iraqi government to get their facilities established. It's their responsibility to maintain the facilities, it's their responsibility to provide the guards," said a senior U.S. military official in Baghdad.
Col. Daniel Britt, who heads the U.S. military's National Police Transition Team, which advises the detention center staff, said the conditions were "appalling" but met international standards. U.S. soldiers visit almost daily, Britt said.
Iraqi authorities also say that the conditions comply with their laws and invited a reporter and photographer Thursday to tour the facility.
National Police Col. Thamir Mohammed Ismail Husseini, one of the commanders at the detention center, urged detainees to speak up about any problems they had experienced. "You can say what you want, even complaints," he said.
None of the detainees nearby took him up on his invitation. U.S. officials say Husseini is connected to Al Mahdi, a Shiite Muslim militia loyal to Muqtada Sadr, a radical anti-U.S. cleric. American commanders blame Al Mahdi for a campaign of sectarian killings aimed at driving Sunni Muslims out of west Baghdad. Most of the detainees here are Sunnis.
U.S. officials say jail staffers release fellow Shiites more quickly than they do Sunnis. "The Shiites will just get released, just let go. The paperwork will be legit, and they just disappear," a U.S. military official said.
According to Iraqi law, detainees should be brought before a judge within 72 hours of their arrest. Most stay for about two months, said Gen. Kareem Ali Chazrage, commander of the National Police division that manages the detention center.
"Sometimes the judicial process is slow, but it is not our fault," Husseini said.
U.S. officials say their own detention centers also have become more crowded since the security plan began Feb. 13 but that they are coping better than the Iraqis.
"There's a flow on the U.S. side and a bunch of bottlenecks on the Iraqi side," said Lt. Col. Steven Miska, commander of the combined U.S. and Iraqi Forward Operating Base Justice in the northwest neighborhood of Kadhimiya. The neighborhood contains the National Police detention center, which once held Saddam Hussein's military intelligence headquarters and was the site of his execution.
Once Husseini left, many detainees said they had been held too long on charges they didn't understand, some unable to contact their families.
Raqi Mishal, 32, a Sunni, had bloody gashes in his forehead and right shoulder. A bandage barely covered a deep, seeping wound in his right bicep.
He said he had been wounded two weeks earlier in a mortar attack on his home in the south Baghdad neighborhood of Dora. "I came to the hospital for that, and they brought me here," Mishal said, insisting that he did not know why he had been detained.
The jail's lone medic, who works out of a makeshift clinic, gave him bandages but no medication, Mishal said. Chazrage confirmed that the jail has had trouble stocking medication.
Khalid Hashimi, 24, pointed to his forearm and calf, where he developed a scaly rash after he was detained by the Iraqi army five months ago in Baghdad's Yarmouk neighborhood. The medic gave him a cream, he said, but it hasn't helped.