The 55-year-old Tshisekedi succeeds Joseph Kabila, the strongman who governed the largely impoverished and corruption-riddled Central African country for 18 years before stepping down under pressure. "We are committed to building a modern, peaceful, democratic and caring state for every citizen," the new president said, "a state that will guarantee the happiness of all."
He called on the troubled nation to engage in a new battle, one for "the well-bring for each citizen of this beautiful country." Kabila watched from behind mirrored sunglasses as the extraordinary scene of an opposition figure becoming president unfolded. When Kabila left the dais, some in the crowd booed.
Tshisekedi also called for national reconciliation in the wake of the disputed Dec. 30 election. The balloting was marked by allegations of large-scale fraud and suspicions of a backroom deal by Kabila to install Tshisekedi over another opposition candidate who according to leaked electoral data was the real winner.
But many Congolese appeared satisfied just to see Kabila go and relieved to witness a peaceful change of power in a politically repressive country with a history of violent coups. Supporters of Tshisekedi stormed the People's Palace, which houses the legislature, for a glimpse of the inauguration.
The new president declared that Congo will not be a nation of "division, hate or tribalism" and spoke of "fundamental rights." He vowed to take on corruption, asserting that $16 billion to $20 billion is lost each year to graft, and rid the country of its dozens of rebel groups. And he surprised observers by announcing his government will free all political prisoners.
It is unclear how many political prisoners are held in Congo "simply because they keep changing — they arrest people in Congo every day for nothing and release some hours later," said Jean-Mobert Senga, a researcher with Amnesty International. More than 100 were arrested in post-election violence, some arbitrarily, he said.
"I have no reason to doubt" the release will happen, Senga said. "It is in his interest to do what he promised to do. Otherwise, people will quickly lose trust." The largely untested Tshisekedi has inherited much goodwill from his father, the late opposition icon Etienne Tshisekedi, who pursued the presidency for decades. In his inaugural address, Tshisekedi referred to his father as "president" to wild cheers.
Tshisekedi's charismatic father had posed such a challenge to Kabila that after he died in Belgium in 2017, Congo's government did not allow his body to be brought home. His son's spokesman has said that will be corrected soon.
Many Congolese hope Tshisekedi will bring change after Kabila, who in his final address on Wednesday night urged the country to unite and support the new leader. But Tshisekedi faces the challenge of working with a legislature dominated by members of Kabila's ruling coalition. That could hurt efforts to bring about dramatic reforms in Congo, a mineral-rich country of more than 80 million people.
"One must transform these words into actions," said Ben Mpoko, Congo's ambassador to South Africa and an influential member of Kabila's ruling coalition. "We have lost much in wars and quarrels. We have no time to lose."
Few had expected an opposition victory in Congo, where Kabila had hung on for more than two turbulent years of election delays. Declared runner-up Martin Fayulu mounted a court challenge to Tshisekedi's win, alleging widespread rigging and demanding a recount. The Constitutional Court on Sunday rejected it. Outside court, Fayulu accused Kabila of making a deal with Tshisekedi as it became clear the ruling party's candidate did poorly at the polls.
Observers have said Fayulu, a businessman outspoken about cleaning up corruption, posed a bigger threat to Kabila and his allies. The new president saluted Fayulu in his speech as a "veritable soldier of the people."
Just one African head of state, Kenya's President Uhuru Kenyatta, was seen at the inauguration after the African Union and others in the international community expressed reservations about the election. The United States and others have said they will work with the new leader but have not offered congratulations.
Congo gained independence in 1960. Its first leader, Patrice Lumumba, was removed in a military coup and assassinated in 1961. Mobutu Sese Seko ruled for more than three decades before he was overthrown in 1997 by rebel leader Laurent Kabila, who was assassinated in 2001. Kabila's son, Joseph, then took over at age 29.
On Thursday, Congo's new president caused a few minutes of confusion and worry by pausing during his inauguration speech. It turned out his bulletproof vest had been too tight.
Anna reported from Johannesburg. Associated Press writer Andrew Meldrum in Johannesburg contributed.
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