Joseph Kabila was sworn in Tuesday for another term as president of DR Congo, a job also claimed by his main rival following disputed polls that have plunged the country into deep crisis. The 40-year-old incumbent was confirmed the winner by a Supreme Court the opposition says he packed with loyalists just before the Democratic Republic of Congo\'s November 28 polls. The chaotic vote in Africa\'s second-largest country was criticised by observers and by Kabila\'s main challenger Etienne Tshisekedi, who has proclaimed himself the people\'s president and is planning his own inauguration on Friday. Kabila took the oath vowed to \"safeguard national unity and allow himself to be guided only by the general interest and the respect of human rights.\" The 79-year-old Tshisekedi has stopped just short of calling mass protests and urged the security forces in Africa\'s second largest country to defect and recognise him as the elected president. The veteran opposition leader, a former prime minister under dictator Mobutu Sese Seko, has no militia of his own but the announcement of the results earlier this month had triggered violence in the streets of Kinshasa. Police were heavily deployed across the capital Tuesday, particularly in the eastern Limete district where Tshisekedi\'s Union for Democracy and Social Progress (UPDS) is headquartered. Opposition protestors were dispersed with tear gas there on Monday and an AFP reporter saw several tanks from the Republican Guard stationed across the city. \"It\'s for the people that these tanks are there,\" government spokesman Lambert Mande told UN-supported radio Okapi on Monday. \"It\'s to help their ease of movement and to protect important visitors.\" Kabila, who took over in 2001 after his father Laurent-Desire\'s assassination, risks isolation on the international scene as a result of the election, which the West have condemned as fraudulent. DR Congo\'s Western trade partners were represented at a relatively low level at Kabila\'s inauguration ceremony and the only head of state to attend was Zimbabwe\'s President Robert Mugabe. The United States has said the elections -- just the second in the DR Congo since back-to-back wars from 1996 to 2003 -- were \"seriously flawed\", and Belgium and France have also questioned their credibility. Observers fear the vast mineral-rich country, which is two-thirds the size of Western Europe, could be headed for a crippling institutional crisis, or worse, for a flare-up of civil unrest. Tshisekedi in a speech this weekend urged Congolese citizens \"not only to retain their calm and serenity ... but also to create the climate of confidence that investors are looking for\". But he has also said he would give a \"very large reward\" to anyone bringing him Kabila \"tied up\". Kabila\'s party spokesman Aubin Minaku brushed off the rhetoric. \"Yet another joke,\" he said, calling Tshisekedi a \"bad loser\".