A 43-year-old man has been arrested following searches in Co Londonderry, in what police say is part of an "ongoing terrorism investigation".
The man was taken into custody for questioning following searches carried out by Terrorism Investigation Unit (TIU) in the Columbcille Court area of Derry on Saturday.
Detectives from the TIU have also been granted an extension by court to continue questioning two men and a woman, who were arrested on Thursday under the Terrorism Act.
On Friday, police seized what they believe to be six improvised explosive devices, a machine pistol and a quantity of ammunition in the Stewarts Terrace area of Derry.
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