Burundi's long-ruling leader Pierre Nkurunziza on Tuesday congratulated his hand-picked successor on a "large victory" in the presidential election, though the opposition has vowed to contest the result in court.
Election officials on Monday declared Evariste Ndayishimiye, a former army general chosen by the powerful ruling party as heir to Nkurunziza, the winner of the May 20 poll with 68.72 percent of the vote.
"I warmly congratulate the President-elect Gen. Major Evariste Ndayishimiye for his large victory which confirms that the great majority of Burundians adhere to the projects and the values he embodies," Nkurunziza, who chose not to run after 15 years in power, posted on Twitter.
"We are privileged witnesses to history. May God bless Burundi!"
The strongest opposition candidate, Agathon Rwasa, came in a distant second with 24.19 percent of the vote, but his National Freedom Council (CNL) has rejected the results, alleging cheating by the governing CNDD-FDD party.
CNL spokesman Therence Manirambona said Monday his party was putting together a legal complaint to submit within days "so that the court can take a decision on the massive fraud that marked this electoral farce."
The CNDD-FDD defeated the CNL by a similar margin in the legislative elections held the same day.
No foreign observers were allowed into Burundi to keep an eye on the election process, which went ahead with scant regard to the coronavirus outbreak following a tense campaign marked by violence and arbitrary arrests.
Nkurunziza has been in power since 2005, and his final years in office have been wracked with turmoil.
His third-term election run in 2015 sparked violence which left at least 1,200 dead and pushed 400,000 to flee the country.
Burundi is tightly controlled by the ruling party and its youth wing has been linked to a forceful crackdown against the government's critics.
State security forces have been accused by rights groups and the United Nations of crimes against humanity and abuses such as torture, disappearances, sexual violence and executions.
Ndayishimiye is set to inherit a deeply isolated country, under sanctions and cut off by foreign donors, its economy and national psyche damaged by the years of unrest.
It remains to be seen how much influence Nkurunziza will exert going forward, and how freely his successor can reign.
Nkurunziza was this year elevated by Burundi's parliament to the rank of "supreme guide for patriotism" and he will continue to be chairman of the ruling party's powerful council of elders.
Ndayishimiye is expected to be sworn in for a seven-year term in late August, when Nkurunziza's term ends.