Detectives investigating the murder of a Catholic policeman in Northern Ireland arrested a second man today.
The 40-year-old suspect was stopped in a car on the road between Omagh and Ballygawley in Co Tyrone at 8.20am.
He is being questioned about the murder of 25-year-old Pc Ronan Kerr in Omagh on Saturday, and also about a significant cache of weapons and explosives discovered by police in nearby Coalisland on Tuesday night.
A 26-year-old suspect arrested in Scotland yesterday in relation to the arms find has now been re-arrested over the murder.
Both suspects are being questioned at Antrim police station.
As the 40-year-old man was arrested, police also seized a vehicle for examination.
Police Service of Northern Ireland (PSNI) assistant chief constable Drew Harris said yesterday: "Detectives from serious crime branch who are investigating Ronan's murder have made a significant discovery of arms and munitions - one of the most significant in recent years."
The weapons haul - found in stolen vehicles in garages on the Mountjoy Road in the Co Tyrone town - included Kalashnikov rifles, ammunition, timer power units, detonators, incendiary bombs, components for rocket launchers and other explosive devices, and a quantity of explosives, possibly Semtex.
The first man arrested was taken into custody in Renton, Dunbartonshire.
He was initially questioned about the Coalisland find but was re-arrested in police custody today in connection with the murder.
The development came a day after the funeral of the officer heard a plea for an end to violence from Ireland's most senior Catholic churchman Cardinal Sean Brady.
The murder has been blamed on dissident republicans opposed to the peace process and is believed to be aimed at deterring Catholics from joining the police.
Cardinal Brady told mourners in the Pc's home village of Beragh, Co Tyrone, that people rejected those blamed for killing the new recruit.
He pleaded with parents not to allow their young people to become involved in violence.
PSNI officers and senior Gaelic Athletic Association (GAA) members stood side by side and helped carry the coffin into the Church of the Immaculate Conception in an unprecedented sign of unity.
Cardinal Brady told mourners: "The people have said no, never again, to the evil and futility of violence. They have said an emphatic no to the murder and mayhem of the past. Let there be no doubt that the killing of Ronan Kerr was totally unjustified.
"It was an evil deed, an offence against God and a complete rejection of the belief that human life is sacred."
His killing has sparked unanimous cross-community condemnation.
The funeral procession was accompanied by unifying images that would have been unimaginable during the Troubles.
First Minister Peter Robinson was the first Democratic Unionist Party leader to attend a Catholic Mass, while the presence of Sinn Fein Deputy First Minister Martin McGuinness at the funeral of a police officer also represented a striking break with the past.
In Belfast yesterday, hundreds of people demonstrated for peace in a rally organised by the Irish Congress of Trade Unions (ICTU).
Police sources later said a house was searched in the Dublin area as the investigation widened.
No arrests were made.