Gardai have arrested two men as part of an investigation into the murder of a prison officer in Northern Ireland last year.

Detectives targeting dissident republicans made the arrests in Cavan and Leitrim.

A number of searches were also carried out in the two counties.

Officer David Black was shot dead in Lurgan on November 1st 2012, as he was travelling to work at Maghaberry Prison.

He had served as a prison officer for over 30 years.

His car was found on the Belfast-bound carriageway of the M1 between Portadown and Lurgan, with a number of bullet holes.

Gardai say these arrests are is part of an on-going operation by the Special Detective Unit.

The two suspects, one aged 51 and another aged 34, are being held under Section 30 of the Offences Against the State Act.

They can be held for up to 72 hours.

Pictured above: The funeral of David Black in Co. Tyrone in November last year