Burundi's constitutional court on Thursday dismissed an opposition petition to invalidate the result of a referendum to change the constitution.
"The constitutional court rules that the May 17 referendum took place according to the law," said judge Charles Ndayiragije after dismissing the application by the Amizero y'Abarundi (Burundians' Hope) coalition.
The group had called for the results to be annulled, citing intimidation and arrests during the campaign and on the day of the vote.
The reforms, which passed with 73 per cent voting in favour, extend presidential terms from five to seven years, which could allow President Pierre Nkurunziza to stay in power until 2034.
Nkurunziza, in power since 2005, already sought a third term in 2015 despite a two-term constitutional limit by arguing his first mandate came after being elected by parliament rather than in a general election.
His third-term run plunged the country into crisis, with protests and violence leaving 1,200 dead and 400,000 displaced.