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A crowd of Haitian looters called for help from U.S. soldiers on Tuesday after finding a man buried in the rubble of a building that had been repeatedly scavenged since the devastating earthquake in Port-au-Prince two weeks ago.

A witness told Reuters the man, covered in dust and wearing only underwear, was rescued by soldiers from the U.S. Army 82nd Airborne Division at a ruined building on Rue de Miracle in downtown Port-au-Prince.

The Americans treated Rico Dibrivell, 35, for a broken leg and severe dehydration. Dibrivell said he had been trapped under the building since the Jan. 12 quake.

The military provided no details about how he managed to survive, saying only in a statement late Tuesday that Dibrivell's family said he had been missing for two weeks.

"He got sent to the hospital. He’s going to make it," Specialist Andrew Pourak, one of the rescuers, said.

SLIDESHOW: Devastation in Haiti | HOW TO HELP | FULL COVERAGE

More than 100 people have been unearthed by rescue teams since the quake, and many more by their neighbors, but most of those were in the immediate aftermath and authorities say it is unlikely for anyone to survive more than 72 hours without water. On Saturday, an international team of rescuers unearthed a shop clerk who they believed had been buried since the earthquake.

Hundreds of thousands of other hungry and thirsty children are scattered among Port-au-Prince's squatter camps of survivors, without protection against disease or child predators — often with nobody to care for them.

"There's an estimated 1 million unaccompanied or orphaned children or children who lost one parent," said Kate Conradt, a spokeswoman for the aid group Save the Children. "They are extremely vulnerable."

The U.N. children's agency, UNICEF, has established a special tent camp for girls and boys separated from their parents in the Jan. 12 quake, and who are in danger of falling prey to child traffickers and other abusers. The Connecticut-based Save the Children has set up "Child Spaces" in 13 makeshift settlements. The Red Cross and other groups are working to reunite families and get children into orphanages.

The post-quake needs of Haiti's children have outrun available help. Some youngsters have been released from hospitals with no one to care for them — there just aren't enough beds.

"Health workers are being advised to monitor and send separated/unaccompanied children to child-friendly spaces," the U.N. humanitarian office said in its latest situation report.

The plight of the young is poignant even in a country where the U.N. estimates a third of the 9 million population needs international assistance in the quake's aftermath. "We still have a huge distance to go," said John Holmes, the U.N. relief coordinator.

That was evident in Port-au-Prince's streets, alleys and crumbled doorways, where handwritten messages begged for help. In the Juvenat neighborhood, a group of 50 families hung a white sheet from a doorway, with this plea scrawled in green: "We need food assistance, water and medicine."

It was evident, too, among the thousands pressing against Haitian police at a food-distribution site in the Cite Soleil slum. They swung sticks to beat back the crowd.

Brazilian troops in armored personnel carriers controlled a tightly packed line of earthquake survivors waiting for food in the broiling sun by firing pepper spray and training their guns on the jostling, rowdy crowd. The line stretched between the partially collapsed National Palace and entirely destroyed Supreme Court.

One soldier loaded a shotgun and returned their taunts by shouting back insults in Creole. Some were offended, others amused at hearing a Brazilian trooper insulting them in their own language.

"They treat us like animals, they beat us but we are hungry people," said Muller Bellegarde, 30.

Several left without getting food, fearful of the pepper spray, the soldiers, and thugs who were grabbing food from receivers.

Many said they appreciate the international response and under no circumstances want the Haitian government to handle aid deliveries, but suggested Haitian churches could provide more orderly and respectful venues for distributions, with Haitian communities organizing security.

"The help is good but the way they're doing it is bad. This is anarchy," Thomas Louis, 40, trying to get rice and oil for his two babies, aged 2 and six months. "This is not aid. This is a way to put people down."

The monumental scale of the Haiti disaster — perhaps 200,000 dead, a capital city on its knees — has severely strained the world's ability to get relief supplies through Port-au-Prince's overloaded airport and crippled seaport.

Some 800 to 1,000 aid flights were still awaiting permission to land, a seven-day backlog, U.N. and European officials reported Tuesday. On top of that, "trucks are needed," U.N. spokeswoman Elisabeth Byrs said in Geneva — especially small trucks because "the streets are extremely congested."

The U.N.'s Holmes estimated that 2 million people need food, but only 500,000 have received some so far.

The medical picture has improved, but remains critical. World Health Organization spokesman Paul Garwood said more medical staff is needed, especially rehabilitation specialists, to help with postoperative recovery of 200,000 people who have had amputations or other surgery.

Haitians and volunteers from dozens of countries, working around the clock, were still performing up to 100 amputations a day in some hospitals.

At the General Hospital, Price strode from tent to tent checking on the 81 children under his care. Staff interrupted the tall, balding pediatrician with a string of questions: "Do you know about this baby?" "Where's the medication?" "Where will we sleep tonight?"

Of the nameless, speechless trio, he was treating young Joe for an infection oozing from both eyes. The 7-pound (3-kilogram) Baby Sebastian, in a white diaper decorated with sheep, had diarrhea. The unnamed girl, about 10, lay listlessly and stared upward. She had an eye infection, but would soon be picked up by an orphanage, Price said.

With no clues to their past, Price could only wonder.

"Maybe some of these parents are not even looking because their house was destroyed and they might think the kid was inside," he said. "But maybe the kid was pulled out, so they are missing each other."

Children left alone are everywhere. At one of the 13 Save the Children sites, about 25 children have no adult relatives taking care of them, Conradt said. She said the group has helped some 6,000 children since the quake.

The aid group's "Child Spaces" are cordoned-off areas where children can play under supervision," run around being children, giving them a chance to return to normalcy as much as they can."

Such areas also protect children against the potential for abduction by child traffickers, a chronic problem in pre-quake Haiti, where thousands were handed over to other families into lives of domestic servitude, said Deb Barry, an emergency protection adviser with Save the Children.

She said her organization was working to track down every rumor it hears about threats to stranded children, "but we haven't been able to verify those thus far."

In Geneva, a UNICEF spokeswoman, Veronique Taveau, said the organization had been told of children disappearing from hospitals. "It's difficult to establish the reality," she said, but added that UNICEF has strengthened security at hospitals and orphanages.

Save the Children, the Red Cross and other organizations, meanwhile, are trying to establish a joint database of information to try to reunite separated families.

Government spokeswoman Marie Laurence Jocelyn-Lassegue, the communications minister, said Tuesday that Haitian officials have temporarily halted new adoptions because of concerns about corruption and carelessness in the system.

"Some children we don't know if the parents are alive or not," Jocelyn-Lassegue said.

The Associated Press contributed to this report.