Constable Stephen Carroll was shot dead by dissident republicans when he went to answer a distress call on 9 March last year.
The men, who are in their 20s and 30s, are being questioned at Antrim police station.
A teenager and a 38-year-old man have previously been remanded in custody charged with the murder.
The Continuity IRA said it killed Constable Carroll, who was 48 and a married man from Banbridge.
He was murdered two days after the Real IRA shot dead two soldiers outside Massereene Barracks in Antrim.