Detectives in the North are continuing to question five men over the murder of policeman Ronan Kerr, who was blown up by dissident republicans earlier this year.
Catholic constable Kerr, 25, was killed when a booby-trap bomb exploded under his car outside his home in Omagh, Co Tyrone, on April 2.
The five men were detained yesterday in a major security operation that involved around 200 officers.
Police have confirmed the arrests were connected to the murder and associated incidents.
Searches were also carried out in Coalisland, Co Tyrone, and Toome, Co Antrim, as well as Bellaghy and Ballyronan, south Derry.
All five suspects were arrested under the Terrorism Act and have been taken to the Serious Crime Suite at Antrim police station for questioning.
A number of items were seized during the police searches including clothing, mobile phones, computers and vehicles. They have been removed for forensic examination and analysis.
A man aged 22 was detained in Coalisland, two men, aged 27 and 46, were arrested in Toome, a 37-year-old was held in Bellaghy and a 33-year-old in Ballyronan.
The officer in charge of the investigation, Detective Superintendent Raymond Murray, said police were determined to pursue every possible line of inquiry.
A £50,000 reward remains on offer for information leading to the arrest and conviction of those responsible for Constable Kerr’s murder.