The Black Hawk helicopters disgorged US troops in combat gear who then moved to secure the Haitian capital’s main hospital, where staff have been overwhelmed by huge numbers of seriously injured patients.
Their arrival brought crowds of quake survivors camped out in the park opposite the palace rushing to its iron railings hoping for handouts of food.
“We do not know exactly what they have come to do but I think they are here to help us, so we tell them welcome,” said one observer, 40-year-old Alex Michel.
In a bid to accelerate the arrival of humanitarian aid and stem looting and violence, the UN Security Council agreed to temporarily add 2,000 UN troops and 1,500 police to the 9,000-member peacekeeping mission in Haiti.
But international doctors said disease would be the next big challenge for tens of thousands of Haitians left injured and homeless when the massive quake struck a week ago.
As the US and UN deploy more troops to secure the relief operation, hundreds of looters have been swarming over damaged stores in downtown Port-au-Prince, seizing goods and fighting among themselves.
UN relief agency officials said the security situation was under control and had not hampered distribution of food rations to 270,000 Haitians so far.
“The situation is tense but calm. Of course there are lootings because the population is on edge,” Elisabeth Byrs, spokeswoman of the UN Office for the Coordination of Humanitarian Affairs, said in Geneva.
Haitian officials say the death toll from the magnitude 7 earthquake that destroyed much of the capital on January 12 was likely to be between 100,000 and 200,000.
Some 52 rescue teams from around the world continued the race against time to find people still alive under the rubble of collapsed buildings. They have saved about 90 people.
“There is hope, because of the conditions, a mild climate and air pockets in the debris due to the way houses are constructed,” Byrs said.
More than 11,000 US military personnel are on the ground, on ships offshore or en route, including some 2,200 marines with earth-moving equipment, medical aid and helicopters.
Haitian President Rene Preval said US troops will help UN peacekeepers keep order on Haiti’s increasingly lawless streets, where overstretched UN and Haitian forces have been unable to provide full security. Gunfire could be heard through Monday night.
US Defence Secretary Robert Gates said US forces would not play a police role but would defend themselves and “have the right to defend innocent Haitians and members of the international community if they see something happen”.
Medical teams pouring into Port-au-Prince to set up mobile hospitals said they were overwhelmed by the casualties and warned of the immediate threats of tetanus and gangrene as well as the spread of measles, meningitis and other infections.
The World Health Organisation (WHO) said yesterday at least 13 hospitals were working in or around Port-au-Prince.
The UN agency was bringing in emergency medical supplies yesterday to treat 120,000 people over the next month, WHO spokesman Paul Garwood told reporters in Geneva.
“We are not past the emergency phase yet, but we are starting to look at the long term,” said Margaret Aguirre of the International Medical Corps, whose staff had helped with 150 amputations so far.
“There is a risk of cholera and tetanus, and a huge need for mobile medical units,” she said.
AIDS, tuberculosis and malaria are rampant in Haiti, many children are malnourished and hygiene was a challenge even before the quake.
Under the protection of US troops, food and water and other emergency supplies have begun arriving more regularly at the congested US-run airfield in Port-au-Prince.
US military officers hope to reopen Port-au-Prince’s shattered seaport in two or three days, but are relying for now on airdrops of food and water to those waiting in makeshift refugee camps.
The World Food Program (WFP) said 270,000 people had received emergency food assistance.
“We are looking at having 10 million ready-to-eat rations going out in the course of the coming week,” WFP spokeswoman Emilia Casella said in Geneva. That would feed half a million people three times a day for a week.
Fuel prices have doubled, and there were long queues outside gas stations, where cars, motorbikes and people with jerrycans have lined up. Haitian police stood guard at some.
One sign of the return to normality was the emergence of street vendors offering fruit and vegetables for sale.
Although a few street markets began selling vegetables, charcoal, chicken and pork, tens of thousands of survivors across the city were clamouring for help.
Former US President Bill Clinton, the UN Special Envoy to Haiti, did his bit for the aid effort on Monday by unloading bottles of water from a plane after landing in Port-au-Prince.
“It’s astonishing what the Haitians have been able to accomplish, performing surgeries at night... with no anaesthesia, using vodka to sterilise equipment,” he said after touring a hospital where supplies were very tight.
World leaders have promised massive amounts of assistance to rebuild Haiti and President Preval appealed to donors to focus not just on immediate aid for Haitians but also on long-term development of the poorest nation in the western hemisphere.
Dominican President Leonel Fernandez proposed the creation of a $2 billion-a-year (€1.39bn) fund to finance Haiti’s recovery over five years.
EU institutions and member states have offered more than €400 million in emergency and long-term assistance.
US President Barack Obama spoke with Brazil’s President Luiz Inacio Lula de Silva on the need for the two governments and Canada to take the lead in organising donor conferences, a Brazilian official said.
The United States agreed to take in Haitian orphans who are being adopted by US citizens and are legally confirmed as eligible for adoption abroad by Haiti.
Obama’s handling of the Haitian crisis won the approval of 80% of Americans polled by CBS News and may have helped a rise in his overall job approval rating to 50% from an all-time low of 46% last week, CBS said.