Two 34-year-old men have been arrested by Terrorism Investigation Unit in the Shantallow and Galliagh areas of Londonderry.
The arrests follow two searches of residential properties in the area.
The two men have been taken to the Serious Crime Suite at Musgrave Police Station in Belfast.
“Today’s searches and arrests are part of an ongoing investigation into violent criminality linked to Óglaigh na hÉireann," Detective Inspector Keith Wilson said: “We understand the impact our operational activity can cause the local community and want to assure them we seek to plan activity to maximise safety, minimise any disruption, and remain grateful for their continued support.
"I also would ask anyone with information or concerns about illegal activity to contact us in confidence on 101.”
The arrests come after two consecutive nights of disorder in the Galliagh area of the city with pallets being burnt, blocking off roads.
Fire crews were forced to withdraw from the Galliagh area of Londonderry on Monday after coming under attack in disturbances which were linked to the removal of material for a controversial bonfire.
UPDATE: The men have since been released.
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