Zambia\'s new President Michael Sata took office Friday, kicking off with a pledge to crack down on the rampant corruption that turned voters away from his predecessor. Sata, who five years ago threatened to chase the Chinese out of the country, said after his swearing-in that he welcomed all investors but wanted them to help improve the lives of Zambians.\"We welcome investors. Zambia can never achieve development without you all,\" he said, but added: \"I promise to put Zambia first.\"\"Corruption has been a scourge in this country and there is a wide link between corruption and poverty. Corruption is morally unacceptable and must be fought with the vigour that it deserves,\" said Sata. The outgoing Rupiah Banda sat nearby, dabbing tears from his face with a white handkerchief.US President Barack Obama congratulated Zambia on its \"historic\" election, saying he looked forward to working with Sata while also hailing Banda\'s contributions to the country\'s democratic development and his acceptance of the results.\"I hope that all Zambians will find common ground as you address the challenges and seize the opportunities facing your country and our world,\" he said.Banda had campaigned on the strength of Zambia\'s economy, which grew 7.6 percent last year, and pointed to new hospitals, schools, roads and electricity projects as proof of his success. But Sata took 43 percent of the vote to Banda\'s 36 percent, by harnessing the anger of the youth and the unemployed who have yet to see change in their daily lives. The election was marred by sporadic violence that left two people dead on Thursday, but Lusaka\'s streets were joyous as Sata\'s supporters scaled walls and climbed trees in hopes of glimpsing his swearing-in.Scores of police on horseback or in riot helmets stood by, but Banda\'s speedy concession of defeat diminished the chance of more unrest. \"Speaking for myself and my party, we will accept the results. We are a democratic party and we know no other way,\" Banda said in his farewell speech.Observers said the violence had not compromised the elections, and found no evidence of fraud. Zambia is now one of the few African countries to have the ruling party change democratically twice since independence, a fact that regional powerhouse South Africa said \"bodes well for the consolidation of democratic culture on the continent\". Banda\'s Movement for Multi-party Democracy (MMD) had ruled since Frederick Chiluba unseated independence leader Kenneth Kaunda in the first democratic elections in 1991. But Chiluba\'s graft trial dented the party\'s reputation. Convicted in London, Chiluba was acquitted in Lusaka. Banda\'s government refused to appeal, and he disbanded the team that brought the case to trial. Sata\'s critics fear that this strong-willed firebrand, who has expressed his admiration for Zimbabwe\'s President Robert Mugabe, could prove authoritarian.The kwacha fell sharply after the outcome with Citigroup saying uncertainty around the new government \"will keep the currency on the back foot\", and a drop in copper prices will contribute. Sata\'s proposed policies, however, fall well within the mainstream -- including a planned review of the tax code that would likely result in higher mining taxes, which he says will help the two thirds of Zambians living on less than two dollars a day. \"His win was very much driven by people in the informal sector, people who felt they were left out of the economic boom,\" said Lee Habasonda from the Southern Africa Centre for the Constructive Reconciliation in Lusaka.While Sata once railed against Beijing\'s growing presence, he now will be in a position to win more concessions from Chinese companies, said Matthew McDonald of the Centre for Chinese Studies in South Africa.Since 2007, China has poured an estimated $6.1 billion into Zambia. \"This is an excellent opportunity for an African country to leverage its position with regards to Chinese investment,\" said McDonald.