Police in Burundi have arrested former President Domitien Ndayizeye in front of the senate building in the capital.
Mr Ndayizeye is accused of involvement in an alleged plot
Mr Ndayizeye was detained and taken off for questioning after the Senate lifted his immunity as a member of the house.
He is accused of involvement in an alleged coup plot earlier this year, the head of Burundi's intelligence told the AP news agency.
Mr Ndayizeye was Burundi's president from 2003 until August last year, when he handed over power after elections.
"He is on the list of coup plotters to be arrested," said Intelligence chief Maj Gen Adolphe Nshimirimana. Police are also looking for some of the former president's aides.
Mr Ndayizeye, a Hutu, was leader under a power-sharing agreement aimed at ending a decade of conflict between majority Hutus, and the Tutsis who have traditionally dominated the country.
Last August, he was succeeded by Hutu former rebel leader Pierre Nkurunziza.