Two men are due in court in Derry this morning, charged under the Terrorism Act.
The pair, aged 43 and 23, are charged with possession of firearms with intent to endanger life.
The arrests were made after a car was rammed by police on the Foyle Road, on Tuesday night. The 23 year old was in the vehicle, the other man was detained in a follow up operation.
A 54-year-old man and 16-year-old boy detained at the same time have been released without charge.