3 people have been arrested in connection with the murder of a prison officer in the North.

Gardai in Dublin this morning detained a 31-year-old woman and a 44-year-old man.

They are now being held at Ballymun Garda station.

Meanwhile police in the North have arrested a 36-year-old man who is being questioned in Co. Tyrone.

David Black was shot on a motorway in Co. Armagh on November 1st while en-route to work at the top security Maghaberry Jail in County Antrim.

Group claimed responsibility

A few weeks after the killing a new republican paramilitary group claimed responsibility for the murder.

Calling itself the IRA the group said the killing was in direct response to the conditions in Maghaberry Prison.

In the statement to The Irish News newspaper group the group said it was a successor to the provisional IRA which disbanded after the Belfast agreement in 1998.

The new organisation is a coalition of dissident groups formed earlier this year.

It said the killing was a direct response to what it said was the degradation of Republican Prisoners at Magaberry Jail where nationalists have been protesting against strip searches.