Two men arrested in connection with the murder of Constable Ronan Kerr have been released "unconditionally".
Constable Kerr was killed by a bomb under his car outside his Omagh home on Saturday 2 April.
Brian Carron, 26, from the Dungannon area, was arrested in Renton, West Dunbartonshire, four days later.
Sean McKiernan, 40, of Omagh, was arrested on 7 April. Both were released on Tuesday. A 33-year-old remains in custody.
Mr Kerr's funeral witnessed unprecedented scenes - with police officers and members of the Gaelic Athletic Association uniting in his memory, as well as politicians from across all the main Northern Ireland parties.