Tanks have been deployed in Kinshasa in case of opposition protests as Joseph Kabila prepares to be sworn in for a second term as Democratic Republic of Congo's president. The Supreme Court has confirmed that Mr Kabila gained the most votes in the November election. But observers have criticised the poll and opposition leader Etienne Tshisekedi has declared himself president. He says he will be sworn in on Friday. Mr Tshisekedi, who enjoys strong support in the capital, Kinshasa, has called on civil servants and the security forces to take orders from him, rather than Mr Kabila. He said he was offering a reward for the capture of Mr Kabila. An aide of Mr Kabila said the call was "criminal". Following the criticism of the election, only a handful of African heads of state have confirmed their presence at Mr Kabila's inauguration. The foreign minister of former colonial power Belgium has cancelled plans to attend the ceremony. The elections were the first Congolese-organised polls since the end of a devastating war in 2003 which left some four million people dead. He also called on the security forces and civil servants to disobey Mr Kabila's orders. Mr Tshisekedi led the campaign for democracy under former leader Mobutu Sese Seko but these were the first elections he has contested. He boycotted the last poll in 2006, organised under the auspices of the United Nations, after claiming they had been rigged in advance. Mr Kabila has been president since 2001 following the assassination of his father, Laurent. Last week, Mr Kabila admitted there had been mistakes in the election process. But he rejected concerns that the results lacked credibility. The US-based Carter Center, which sent observers to the election, said the vote was too flawed to be credible. The US state department called for a review of irregularities and the EU described parts of the election process as "chaotic". However, the African Union described the elections as a success.