Two men are being questioned about suspected republican paramilitary crimes in Northern Ireland.
The two, who are understood to be related, were arrested in Bellaghy, Co Derry, and taken to the anti-terrorist holding centre in Antrim.
Police would not give details of any alleged offences, or whether the arrests were linked to mainstream or dissident republicans.
Sinn Féin hit out at the arrest operation, and said a complaint had been lodged with the Northern Ireland Police Ombudsman.
Mid Ulster MLA Geraldine Dougan claimed officers continued to search the two men's homes after the early morning arrests.
She added: 'The attitude of the PSNI on the ground is reminiscent of the worst excesses of their disgraced predecessors in the RUC.'