A 34-year-old man has been arrested under the Terrorism Act as part of a probe into violent dissident republican activity.
Detectives from the PSNI’s Terrorist Investigation Unit said the man was detained in the Coalisland area of Co Tyrone on Tuesday morning.
He is currently in the serious crime custody suite at Musgrave PSNI station being quizzed about terrorist activities.
The arrest is linked to the seizure of a haul of guns and ammunition found in a shed in the Coalisland area in 2011
The search was carried out as part of the investigation into the murder of PSNI constable Ronan Kerr.
He was murdered when an undercar booby trap device exploded under his car in April 2011 as he headed to work.
A new group of dissident republicans carried out the murder.