Prison officer murder: two suspects freed by police
The prominent Irish republican Colin Duffy has been released from custody after being arrested in relation to the murder of prison officer David Black.
David Black, 52, was shot dead on a motorway on Thursday as he was driving to work at Maghaberry prison.
Mr Duffy, 44, and a 31-year-old man, were detained in Lurgan on Friday.
Both men have been released unconditionally but a 29-year old man arrested in the Irish Republic on Friday is still being questioned.
He was arrested by the Irish police in County Leitrim and is being questioned in Carrick-on-Shannon.
Earlier, the United States Secretary of State Hillary Clinton said the murder of prison officer David Black was an outrageous and cowardly act.
Mr Black was shot on the M1 on Thursday morning as he drove to work at Maghaberry jail.
Mrs Clinton said the US was resolute in its support for Northern Ireland's embrace of peace and reconciliation.
Mr Black's funeral is due to take place on Tuesday.
The Crimestoppers charity has offered up to £10,000 for information leading to the conviction of those responsible for the 52-year-old's murder.
Mr Black, from Cookstown in County Tyrone, was driving to work when a car pulled up beside his vehicle on the motorway in County Armagh and fired a number of shots. His car veered into a ditch and he died at the scene.
On Friday, the senior officer investigating the murder appealed for information about the movements of Mr Black's car and that of his killers.
Mr Black was driving a black Audi A4, with the registration number HHZ 1560.
Officers want to hear from anyone who saw it after 07:00 GMT on Thursday when it travelled from Cookstown, through Stewartstown and onto the Tamnamore roundabout before going onto the M1 eastbound.
The killers were driving a dark blue Toyota Camry which had an Irish registration number, 94 D 50997. It was found burnt out in Inglewood in north Lurgan at 07:50 GMT.
Mr Black, a father-of-two, was the first prison officer to be murdered in Northern Ireland in almost 20 years.
The Police Service of Northern Ireland (PSNI) said they believed dissident republican paramilitaries were responsible for the attack.
He was the 30th prison worker to be murdered by paramilitaries since 1974 in Northern Ireland.