Police in Northern Ireland have made five arrests and are carrying out a major search operation in connection with the murder of PSNI officer Ronan Kerr.
The 25-year-old policeman was killed when a bomb exploded under his car in Omagh in April. His murder caused widespread revulsion and saw both GAA members and Mr. Kerr's police colleagues carry his coffin for the funeral.
Dissident republicans have been blamed for the killing.
On Tuesday, 200 officers carried out seven searches in counties Tyrone, Antrim and Derry.
The five men arrested are aged from 22 to 46. A 22-year-old man was arrested in Coalisland, County Tyrone; two men aged 27 and 46 were arrested in Toomebridge, County Antrim; in Bellaghy, County Derry, a 37-year-old man was arrested, while in Ballyronan, County Derry a 33-year-old man was arrested.
All five men have been taken to Antrim police station for questioning.
In Toomebridge there was a heavy police presence with three police Land Rovers, armed police, two police cars and a police van at a pub on the Hillhead Road.
In Coalisland, a car was removed and there was a heavy police presence with Land Rovers on the outskirts of the town.
The investigation is being led by detectives from the Serious Crime Branch.
Police said clothing, mobile phones, computers and cars had all been seized for forensic analysis.
Detective Superintendent Raymond Murray told reporters: "our determination to pursue every possible line of enquiry remains undiminished.
"The investigation is progressing and police have been encouraged by the support and assistance which has been forthcoming from across the community."
Police said a £50,000 reward remains on offer for information leading to the arrest and conviction of those responsible for Constable Kerr's murder.
Constable Kerr had just finished his police training when he was killed. He was the second officer to have been murdered since the Royal Ulster Constabulary became the PSNI in 2001.
