A Burundian court has acquitted three civil rights activists who had been handed 10-year jail terms for undermining state security, their organisation said on Thursday.The decision is a rare victory for rights activists in the troubled nation.Emmanuel Nshimirimana, Aime Constant Gatore and Marius Nizigiyimana, members of the campaign group Parcem, had been planning a human rights workshop when they were arrested in June 2017."Justice has recognised that our colleagues are totally innocent," said Faustin Ndikumana, the head of Parcem, who said the verdict was overturned on appeal.A judicial source confirmed the acquittal, but declined to give further details.The three men remain in custody. "Administrative steps are underway to regain freedom," Ndikumana said.The men were not present during their trial in March, when the prosecution said they were found in possession of documents about the rights workshop - which included comments from opposition activists but not government officials.Burundi has been in a serious political crisis since President Pierre Nkurunziza in April 2015 sought a fiercely-contested third term in office.The violence has claimed at least 1,200 lives and displaced more than 400,000 people between April 2015 and May 2017, according to estimates by the International Criminal Court (ICC), which has opened an investigation."We demand that all Burundians who are in prison for their opinions be released," Ndikumana said.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.