Two men are being questioned over the murder bid on a policeman in Northern Ireland.
Police Constable Peadar Heffron lost a leg after a bomb exploded under his car in Randalstown, Co Antrim, earlier this month.
The Police Service of Northern Ireland detained a 34-year-old man in west Belfast, while a 33-year-old man was held in the north of the city.
Pc Heffron, 33, who only recently regained consciousness after the January 8 bombing, was attacked by dissident republicans opposed to the peace process.
It is understood the group responsible targeted the young officer because he is a Catholic who has risen to prominence as an Irish language specialist for the police and is captain of the Police Service of Northern Ireland gaelic football team.
Pc Heffron represents the changing face of a service which is steadily redressing a traditional religious imbalance in policing north of the border.
Last year he was among officers who attended the first meeting at which discussions in Londonderry between Policing Board officials and members of the public were conducted in the Irish language.
He once played for Kickhams Creggan, a Gaelic Athletic Association (GAA) club based in Randalstown.
The recently married officer, who has served with the police for nine years, had just left his home to start work in west Belfast when the device exploded under his blue Alfa Romeo car.
Shocked neighbours rushed to help Pc Heffron, whose car careered sideways on the slippery Milltown Road at around 6.30am.
He was taken to hospital for emergency treatment before being transferred to the Royal Victoria in Belfast, where he remains in a critical condition.
The attack happened two miles from the Massereene Army barracks, where two soldiers just about to leave for Afghanistan were shot dead by the Real IRA last March.
Sappers Mark Quinsey, 23, and Patrick Azimkar, 21, were gunned down as they collected a pizza delivery outside the gates of the base.
Democratic Unionist leader Peter Robinson, Sinn Fein Deputy First Minister Martin McGuinness and Irish Prime Minister Brian Cowen, as well as other politicians and church leaders on all sides, have condemned the bombing.
It is the latest in a series of attacks by dissidents and was virtually identical to one close to the PSNI headquarters, in which an officer's girlfriend narrowly escaped death last October.