A Burundian man recently deported from the United States after failing to receive political asylum has been detained without charge back home, activists said on Saturday.Clement Nkurunziza has had no access to a lawyer since his March 22 arrest, said the group iBurundi, which monitors alleged government abuses.Police spokesperson Pierre Nkurikiye confirmed Nkurunziza is in custody but gave no details.Nkurunziza was arrested after arriving on a plane from the US, iBurundi said.Over 1 000 people had signed an online petition urging the US not to send Nkurunziza back to Burundi, saying "his life would be in jeopardy."But another group of Burundians signed a separate petition urging his deportation, alleging that he had a role in the killings of students during his time as president of the students' union at the University of Burundi in the 1990s during the country's 13-year civil war."When supporters of the Burundian government saw the petition urging the US government to not deport him, they jumped on it and started saying he should be sent to Burundi to be jailed," iBurundi said. It called for an independent investigation of those allegations.Burundian prosecutors have not said what crime Nkurunziza is likely to be charged with.Nkurunziza had fled Burundi after urging the president to retire after two terms in 2015. Deadly protests broke out when President Pierre Nkurunziza successfully sought a third, disputed, term, leaving an estimated 1 200 people dead.The two men are not related.KEEP UPDATED on the latest news from around the continent by subscribing to our FREE newsletter, Hello Africa.FOLLOW News24 Africa on Twitter and Facebook. The International Criminal Court judges last year authorized an investigation into allegations of state-sponsored crimes during the recent political upheaval in the East African nation that the U.N. human rights chief has called one of "the most prolific slaughterhouses of humans in recent times."Burundian authorities have repeatedly denied allegations of serious rights abuses, saying they are the victim of propaganda by exiles opposed to the government.Burundi's president rose to power in 2005 following the signing of the Arusha accords ending the civil war that killed about 300 000 people. He was re-elected unopposed in 2010 after the opposition boycotted the vote. He said he was eligible for the third term in 2015 because lawmakers, not the general population, had chosen him for his first term. Critics called the move unconstitutional.Burundi now faces a referendum in May on proposed changes to the constitution that would let the president rule until 2034.