Police investigating suspected extreme right-wing activity have arrested a 26-year-old man.
He was detained in Ballymena, Co Antrim, by detectives from the Police Service of Northern Ireland's serious crime branch.
Detective Inspector Andy Workman said: "The 26-year-old suspect has been taken to a police station in Belfast for questioning.
"The investigation is linked to extreme right-wing views about tensions in north-eastern Europe and suspicious activity in a forest in Co Antrim."
Last week four men, aged 29, 30, 36 and 46, were detained at houses in Ballymena and Coleraine in Co Londonderry as part of the same investigation.
They were released pending reports being sent to the Public Prosecution Service.
It is understood the inquiries are not related to munitions finds at Carnfunnock and Capanagh forests earlier this year.