The PSNI’s Terrorism Investigation Unit carried out three searches in Creggan as part of an ongoing terrorism investigation.
Two of the searches are complete, while the third search is ongoing in Creevagh Heights.
During the searches cash, a firearm, suspected firearm, suspected pipe bombs and suspected ammunition have been seized and will be subject to forensic examination, the PSNI stated.
Petrol bombs, rocks, masonry, steel poles and traffic cones were thrown at police, damaging police land rovers at around 4pm.
Drivers are urged to avoid the area.
Superintendent William Calderwood said: "The search in Creevagh Heights is continuing. We appreciate the disruption search activity can have but I want to reassure you of this - our presence in the area and activity we carry out is about keeping people safe. That is our priority and we would appeal for calm."