A man has been arrested in connection with an investigation into the murder of Northern Ireland policeman Ronan Kerr.
The 39-year-old was arrested after searches were carried out in Omagh.
He is being held at the Serious Crime Suite at Antrim police base.
Searches were also carried out yesterday as part of the murder inquiry.
Another man was arrested in Milton Keynes in England yesterday.
Several items were seized for examination, including a truck stopped in Milton Keynes.
Constable Kerr, 25, was killed in a car bomb attack by dissident republicans at his home in Omagh, Co Tyrone, in April last year.