By MICHELLE FAUL and JENNIFER KAY
PORT-AU-PRINCE, Haiti -- Prayers of thanksgiving and cries for help rose from Haiti's huddled homeless Sunday, the sixth day of an epic humanitarian crisis that was straining the world's ability to respond and igniting flare-ups of violence amid the rubble of Port-au-Prince.
Haitian police struggled to scatter hundreds of stone-throwing looters in the city's Vieux Marche, or Old Market. Elsewhere downtown, amid the smoke from bonfires burning uncollected bodies, gunfire rang out and bands of machete-wielding young men roamed the streets, faces hidden by bandanas.
A leading aid group complained of skewed priorities and a supply bottleneck at the U.S.-controlled airport. The general in charge said the U.S. military was "working aggressively" to speed up deliveries.
Beside the ruins of the Port-Au-Prince cathedral, where the sun streamed through the shattered stained glass, the priest told his flock at their first Sunday Mass since Tuesday's earthquake, "We are in the hands of God now."
But anger mounted hourly that other helping hands were slow in getting food and water to millions in need.
"The government is a joke. The U.N. is a joke," Jacqueline Thermiti, 71, said as she lay in the dust with dozens of dying elderly outside their destroyed nursing home. "We're a kilometer (half a mile) from the airport and we're going to die of hunger." Hours later, a frail resident of the home perished in the afternoon heat.
Water was delivered to more people around the capital, where an estimated 300,000 displaced were living outdoors. But food and medicine were still scarce.
The crippled city choked on the stench of death and shook with yet another aftershock Sunday. On the streets, people were still dying, people were on their knees praying for help, pregnant women were giving birth on the pavement, and the injured were showing up in wheelbarrows and on people's backs at hurriedly erected field hospitals. Authorities warned that looting and violence could spread.
At the Vieux Marche, police tried to disperse looters by driving trucks through the crowds, as hundreds scrambled over partly destroyed shops grabbing anything they could. As he ran from the scene with a big box of tampons, Love Zedouni shouted: "I've got no idea what this is, but I'm sure you can sell it."
Police used tear gas to scatter looters at street markets near the collapsed presidential palace. At the Cite Soleil slum, moments after police drove by, a reporter spotted a gunman stealing a bag of rice from a motorcycle rider.
"This is one of the most serious crises in decades," U.N. Secretary-General Ban Ki-moon said as he flew into the Haitian capital. "The damage, destruction and loss of life are just overwhelming."
A reliable death toll may be weeks away, but the Pan American Health Organization estimates 50,000 to 100,000 died in the 7.0-magnitude tremor, and Haitian officials believe the number is higher.
Celebrating Mass outside the once-proud pink-and-white cathedral, now a shell of rubble where a rotting body lay in the entrance, the Rev. Eric Toussaint preached of thanksgiving to a small congregation of old women and other haggard survivors assembled under the open sky.
"Why give thanks to God? Because we are here," Toussaint said. "What happened is the will of God. We are in the hands of God now."
Mondesir Raymone, a 27-year-old single mother of two, was grateful. "We have survived by the grace of God," she said.
But others were angry.
"It's a catastrophe and it is God who has put this upon us," said Jean-Andre Noel, 39, a computer technician. "Those who live in Haiti need everything. We need food, we need drink, we need medicine. We need help."
Were his parishioners being helped? Toussaint was asked. "Not yet," he replied.
The U.N. World Food Program was "pretty well on target to reach more than 60,000 people today," up from 40,000 the previous day, WFP spokesman David Orr said. But U.N. officials said they must raise that to 2 million within a month. The U.S. aid chief, Rajiv Shah, told "Fox News Sunday" he believed the U.S. distributed 130,000 "meals ready to eat" on Saturday, but the need was much larger. "We're really trying to address it," he said.
Some food was still commercially available in the city, but prices had skyrocketed beyond what most people could afford.
In a further sign of the delays, the aid group CARE had yet to set a plan for distributing 38 tons of WFP high-energy biscuits in outlying areas of Haiti, CARE spokesman Brian Feagans said Sunday. He did not say why.
The Geneva-based aid group Doctors Without Borders put it bluntly: "There is little sign of significant aid distribution."
The "major difficulty," it said, was the bottleneck at the airport, under U.S. military control. It said a flight carrying its own inflatable hospital was denied landing clearance and was being trucked overland from Santo Domingo, almost 200 miles away in the Dominican Republic, delaying its arrival by 24 hours.
French, Brazilian and other officials had earlier complained about the U.S.-run airport's refusal to allow their supply planes to land. A World Food Program official told The New York Times that the Americans' priorities were out of sync, allowing too many U.S. military flights and too few aid deliveries.
The U.S. has completely taken over Port-au-Prince airspace and incoming flights have to register with Tyndall Air Force Base in Florida, said Chief Master Sgt. Ty Foster, Air Force spokesman here.
"You won't have the stray cats and dogs allowed to come into the airspace and clog it up," he said.
On Sunday, WFP spokesman Gregory Barrow in Rome was more positive, speaking of "extremely close cooperation" with the U.S. at the airport. But a coordinator here for Spain's international development agency, Daniel Martin, complained that their aid supplies had been diverted to Santo Domingo, and Doctors Without Borders spokesman Jason Cone said the U.S. military needed "to be clear on its prioritization of medical supplies and equipment."
The on-the-ground U.S. commander in Haiti, Lt. Gen. Ken Keen, acknowledged the bottleneck problem. "We're working aggressively to open up other ways to get in here. The ports are part of that," he said on NBC's "Meet the Press."
The White House said Sunday the U.S. Coast Guard ship Oak had arrived at Port-au-Prince harbor, rendered useless for incoming aid because of quake damage, and would use heavy cranes and other equipment to make the port functional.
Other U.S. help was on the way: Some 2,000 Marines should arrive off Haiti on Monday, Keen said, reinforcing 1,000 U.S. troops on the ground.
The general reported "increasing incidents of violence," as a weakened Haitian police force and U.N. peacekeeping contingent were overwhelmed.
In the Port-au-Prince neighborhood of Delmas, a crowd gathered Sunday around the bodies of two accused looters, who had been beaten to death by angry residents. Onlookers said they were among 4,000 prisoners who escaped when the main prison collapsed in the quake.