The three US citizens of Cameroonian origin were arrested on Monday and appeared in court on charges of conspiracy to provide material support to support kidnappings and use of weapons of mass destruction in a foreign country.

Each man held a senior position in an organisation that supported and directed the Ambazonian Restoration Forces, according to the Justice Department.

They "allegedly solicited and raised funds for equipment, supplies, weapons and explosive materials to be used in attacks against Cameroonian government personnel, security forces and property, along with other civilians believed to be enabling the government".

The funds were raised through online chat applications and payment platforms from individuals located in the US and abroad, the department said in a statement.