Police in the North have been attacked with petrol bombs while carrying out searches in Derry.
Some people suffered burns during the violence in the Creggan estate.
The searches followed the discovery of a dissident republican mortar bomb in Strabane in County Tyrone on Saturday.
Officers were targeted after finding what they described as a suspicious object while carrying out searches for New IRA bomb-making equipment.
The occupants of 15 homes were advised to evacuate to ensure the safety of the community.
Young people engaged in the disorder in the Creggan estate sustained burn injuries during the violence on Monday night, according to PSNI.