Police in the North are investigating after petrol bombs and paint bombs were thrown during unrest in Derry last night.
24 petrol bombs and six paint bombs were thrown in the area around the city walls in the Bogside area.
Police say police came under attack from 'youths throwing missiles including bricks and bottles'.
A laser pen was also shone at a police helicopter.
Up to 40 people were involved in the disorder, which followed similar unrest over the weekend.
The PSNI is urging those responsible to "pull back" from such behaviour, and have called on influential figures within the community to help dissuade young people from taking part in any public disorder.
Superintendent Gordon McCalmont said: “This is the third night that the people of this city have had to put up with unwanted disorder and destruction.
"No one wants to see these despicable scenes on our streets."
He added: "Some of the those involved in last night’s trouble were extremely young teenagers and I have no doubt that this disorder is being orchestrated by much older people and that these youths are being used to attack police and significant symbolic sites around our City Walls."
