PORT-AU-PRINCE (AFP) - US troops led by Marines descended from helicopters onto the ruined Haitian capital Tuesday, as a week after a massive quake the US military ramped up a huge aid operation for desperate Haitians. In a spectacular move, paratroopers from the 82nd Airborne division landed in at least four choppers to secure the ruined presidential palace, a once elegant white building now surrounded by a stinking, squalid refugee camp. From the palace, a 100-strong squad of soldiers headed on foot to the citys general hospital, swamped with injured after the catastrophic 7.0-magnitude quake seven days ago, which the Haitian government says killed at least 70,000. But the arrival at the presidential palace was not welcomed by all of the homeless, destitute refugees who saw it as an affront to Haitis sovereignty. Its an occupation. The palace is our power, our face, our pride, said Feodor Desanges, as some of the 50,000 living rough in the Champ de Mars square in front of the palace shouted abuse. Amid reports of sporadic looting and growing tensions on the streets, the UN Security Council voted unanimously Tuesday to send 3,500 extra UN troops and police to Haiti to help maintain order and protect aid convoys. That will swell the number of UN military and civilian forces in Haiti to around 14,500. Security forces are struggling to control looters in Haitis capital, with gangs swarming through the ruins as Haitian police in combat uniforms fired in the air Monday to disperse them. The international Red Cross said it hoped to resume non-food distribution in a part of the city, after tensions forced them to halt the aid on Monday. While the full scale of the disaster remains unclear, extraordinary stories of children and adults surviving several days under collapsed buildings provide rare glimmers of hope. But with hopes fading seven days after the quake struck, the deputy commander of the military operation in Haiti said US forces would transition from a search for survivors to recovering bodies. We fully expect that we will transition very soon from the search phase to the recovery phase, and obviously we continue to be in prayer, said Major General Daniel Allyn, adding no US survivors had been found in the past two days. Relief efforts are now focusing on the estimated quarter of a million injured and 1.5 million homeless, many of them orphans who lost their parents in the disaster. Some 50 orphans whose paperwork had been processed prior to the quake arrived in the United States for treatment and adoption. In a huge global effort, more than 1.2 billion dollars has been pledged in aid funding for Haiti, United Nations data showed Tuesday. Major national donors included Canada, which has pledged 53.6 million dollars, the United States, which has already paid up 114.4 million dollars, and the European Commission with 486 million dollars promised. Officials have expressed fears the final death toll may top 200,000 and a government minister said Sunday that 70,000 bodies had already been buried. International efforts are also focusing on the rebuilding of Haiti, with a major donors conference to be held on Monday in Montreal. We need to move beyond reconstruction to build a new Haiti, said Canadian Foreign Minister Lawrence Cannon.