“One of the arrested people is French, two of them are bi-national: Malagasy and French. The three others are Malagasy,” Rodellys Fanomezantsoa Randrianarison said late on Thursday.
Patrick Rajoelina, an adviser to President Andry Rajoelina, said two of those arrested had previously worked in the French military.
Madagascar’s attorney general said on Thursday police had arrested the six following what officials said was a months-long investigation.
Madagascar has a history of political violence. Andry Rajoelina, 44, was sworn in as president in 2019 after a hard-fought election and a constitutional court challenge from his rival.
Rajoelina first took power in the deeply impoverished former French colony of 26 million people in a March 2009 coup, removing Marc Ravalomanana. He remained in control at the head of a transitional government until 2014. In the 2019 elections, Ravalomanana challenged Rajoelina, lost, and said the vote was fraudulent.