A 28-year-old man has been charged in connection with the discovery of a mortar device in Church View, Strabane.
He is charged with perverting the course of justice, assisting offenders and recording information of a kind likely to be useful to a person committing an act of terrorism.
He was arrested in Strabane on Wednesday by detectives from the PSNI's Terrorism Investigation Unit.
The device was found near houses on Saturday, September 7.
He is due to appear at Londonderry Magistrates Court this morning.