10 police officers were injured in Derry last night following disorder that lasted hours on Nailors Row.
Fireworks, petrol bombs and other missiles were used to attack police.
One arrest has been made to date.
A number of tactics were deployed in an attempt to de-escalate the situation, including use of the Public Order Dog Unit.
Derry City & Strabane Superintendent William Calderwood called the scenes disgusting and said witnessing officers becoming injured as a result of such violence was not only appalling, but completely unacceptable.
He added that a robust investigation is underway to see those involved brought to justice.
Meanwhile two 14 year olds were arrested after petrol bombs were found in the area of Spencer Road on Friday.
One boy was charged with possession of petrol bombs in suspicious circumstances, while the other was charged with possessing articles for use with petrol bombs.
Both appeared before Dungannon Magistrates Court yesterday.
