Detectives from Strand Road, along with colleagues from the PSNI’s Terrorism Investigation Unit investigating dissident republican activity have arrested four people today.
A number of searches were carried out at residential premises, three in Derry, two in the Dungiven area and one in Limavady.
A number of items, including clothing and electronic devices were seized and have been taken away for further forensic examination.
Three men, aged 49, 21 and 19 were arrested under the Terrorism Act while a 61 year old man was also arrested on suspicion of attempting to pervert the course of Justice.
All four men are currently assisting police with their enquiries.