There appears to have been little planning for the humanitarian effort in the aftermath of the Iraqi government's battle against the Islamic State for control of Fallujah. (Loveday Morris/The Washington Post)

Families fleeing the combat in the Iraqi city of Fallujah have been forced to sleep in the open desert for almost a week, with aid agencies warning that people are at risk of dying as supplies of tents and water run dangerously low.

More than 85,000 people have escaped the city and its surroundings in recent weeks as Iraqi security forces battle to recapture the city from the Islamic State. About 4.4 million people in the country are now internally displaced, one of the highest totals of any country.

The United Nations said the pace of new arrivals caught it off guard, even though tens of thousands of people were known to be trapped in the city before the operation began last month. The Iraqi government, meanwhile, under political pressure to launch an offensive quickly, appears to have prepared little assistance for the fleeing families.

In one hastily expanded camp 15 miles west of Fallujah near Habbaniyah, Mihal Adnan and her four children sat next to their meager belongings. It was their fourth day without shelter of any kind, exposed to dust storms and temperatures in excess of 110 degrees.

Displaced women wait for their tent to be built at a refugee camp west of Baghdad on June 21. (Nawras Aamer/European Pressphoto Agency)

Adnan cradled her 13-year-old disabled son, massaging his cramping muscles as he cried in pain. He had soiled himself, but there were no latrines or water tanks installed that she could use to wash him. The family had missed out on a recent government tent delivery and complained that with supplies running low, priority is given to those with money or connections.

“We’ll sleep here tonight,” she said, indicating the one gray blanket they had between them. “What else can we do? We are desperate. We don’t have anything.”

Nearby, men scuffled over a pack of bottles of water as a truck drove around, throwing them out to families.

“We’ve been treated like dogs,” said 72-year-old Mohammed Jassim Khalil. “What’s my guilt in all this?”

His family had been sleeping out for six days and had just managed to get a tent.

“I wish a mortar shell had landed on my house in Fallujah and killed me,” added Ismail Mohammed Hussein, 51. “It’s better than living like this.”

A boy crouches down during a sandstorm in a camp for families displaced from Fallujah. (Loveday Morris/The Washington Post)

The Norwegian Refugee Council said conditions in the camps are getting worse. Pregnant women, children, the elderly and those with disabilities are particularly vulnerable, with some collapsing from exhaustion, relief workers say.

“The situation is deteriorating by the day, and people are going to die in those camps unless essential aid arrives now,” said Nasr Muflahi, the organization’s director in Iraq. “What we’re seeing is the consequence of a delayed and heavily underfunded response with an extreme toll on the civilians fleeing from one nightmare and living through another one.”

The United Nations says it is severely underfunded as it deals with an unprecedented number of people displaced globally, with 1 out of every 113 people in the world unable to safely return home.

Iraq has claimed victory in Fallujah, but only a third of the city has been cleared of the militants, according to the U.S.-led coalition, and no one knows exactly how many people remain trapped inside. The United Nations has warned that more may flee as Iraqi forces advance, adding strain in the already underserved camps.

U.N. officials have appealed for $17.5 million in emergency funding.

Families arrive at the camps with harrowing stories of life under the rule of the Islamic State militants who controlled the city for nearly 2½ years.

Food supplies were low for months, with the city besieged by security forces and bombarded with artillery and airstrikes. The journey out was a perilous one; Islamic State gunmen initially shot at those leaving.

Falah Hussein Ali held up his arms to show the deep bruises that he said resulted from being whipped with electric cables.

He said he was in an Islamic State prison when the operation began and was freed by Iraqi security forces. He said he was arrested and held for 20 days as men in the Nazzal neighborhood were rounded up after an Iraqi flag was raised in the area overnight.

“We didn’t want [the Islamic State] there,” he said. “But they brought us from one death to another kind of death. What kind of life is this?”

Ghassan Abou Chaar, an emergency coordinator for Doctors Without Borders, said that the toll in the camps is both physical and mental.

“People are at breaking point,” he said.

Adding to the stress for families is that all men of fighting age are detained for security screening, leaving women and children to cope by themselves until male family members are released.

Adnan’s husband and 17-year-old son are still in detention.

“If the government can’t help us, they should at least release our men,” said one woman from the Mualimin neighborhood of Fallujah, declining to give her name as she criticized the government response. “We ran away from Daesh, from the bombing, from the hunger, and we find this,” she said, using an Arabic acronym for the Islamic State.

Many complained that they are not allowed to leave Iraq’s Anbar province, even for medical treatment or even if they have family in Baghdad, 40 miles east. With residents from the largely Sunni province considered a security threat, access is severely restricted.

In a more established camp outside the nearby town of Khaldiyah, families are given a cooked meal each day, and there were limited latrines and water tanks.

Some families said that despite the hardships, life was better than it was under the Islamic State.

“Life here is like a prison,” said 94-year-old Mehdi Saleh Abed, sitting in the shade of a tent. “But living here in the dust is better than Daesh.”

An aid group was delivering 100,000 pounds of food supplies, with dust whipping through the barren rows of tents as people lined up to collect it — but families did not have basics such as portable stoves to make use of the sacks of flour and rice that were being handed out.

“It’s a complete disaster,” Jeremy Courtney, founder of the Preemptive Love Coalition, the aid group that was doing the distribution, said of the level of planning. “The government and the international organizations failed to do what they needed to do.”

Facing mass street protests against his government in Baghdad, Prime Minister Haider al-Abadi unexpectedly announced a Fallujah operation in late May in what some analysts said was an attempt to distract from his political problems.

But despite the fact that the battle was launched as a “hasty face-saving exercise” that caught everyone off guard, it was obvious there would be mass displacement as soon the operation was announced a month ago, giving groups time to prepare, Courtney said.

Out of the 85,000 people who have fled, some 60,000 arrived in just three days last week, overwhelming aid agencies.

“No one can be prepared for such a magnitude,” said Bruno Geddo, the Iraq representative for the United Nations’ refugee agency. U.N.-administered camps can house just 16,830 people, he said. Though government camps and large temporary tents that sleep 30 families are making up some of the shortfall, 20 camps are still needed, he said.

On Saturday, three days after the influx began, Abadi said he had ordered a fleet of drinking-water tankers to the camps and asked the Ministry of Health to create an “accurate plan” for how to allocate medics to the area.

The slow response raises concerns about what will happen in the aftermath of a planned offensive to retake the much larger city of Mosul from the Islamic State. The United Nations expects between 600,000 and 1.2 million people to be displaced in that operation.

“I lose sleep over Mosul,” Geddo said.

Mustafa Salim contributed to this report.