Police fear further attacks in N Ireland

Security forces in Northern Ireland were placed on full alert last night amid fears that dissident republicans could unleash an Easter offensive.

Police warned that terrorist groups may be intent on trying to kill more officers, three weeks after the murder of Constable Ronan Kerr in Omagh.

Patrols and on-the-spot security checkpoints are to be set up across Northern Ireland.

A police spokesman said: "Dissident terrorist groups are continuing to identify officers and target them with the single objective of killing them."

The warning came as thousands of mainstream republicans supporting Sinn Fein and the peace process prepared to hold dozens of commemoration parades throughout Ireland to mark the 1916 Rising.

Three men were arrested yesterday when police stopped a car in Keady, Co Armagh.

Police described the arrests as "significant". It is understood a number of undisclosed items were taken away for examination.

Meanwhile, a 33-year-old man from Omagh, Co Tyrone, is to appear in court today after being questioned by detectives investigating Constable Kerr's murder.