France, March 3 -- Federal prosecutors said the arrests followed simultaneous searches in Antwerp and Londerzeel on Sunday. The inquiry, launched last summer, focuses on people living in Belgium suspected of being part of the leadership of the Ambazonia Defence Forces, or ADF.

"Money is reportedly being raised for the armed struggle and for the purchase of arms and ammunition, and instructions for attacks and liquidations are said to be given from Belgium," the federal prosecutor's office said.

Three suspects were remanded in custody by an investigating judge, prosecutors said. One person was released. Authorities said they were working with officials in Norway and the United States, where similar investigations are under way and arrest...