A number of police officers have been injured during disorder in Londonderry, the Police Service of Northern Ireland (PSNI) has said.

Petrol bombs, fireworks and stones were thrown by nationalist youths at police lines during trouble in Nailors Row on Saturday evening.

It followed a major police operation in the city surrounding the annual Apprentice Boys Relief of Derry parade, which passed off without incident.

The PSNI said it was liaising with community representatives to prevent further escalation.

A statement said the trouble presented “a serious risk to the safety of residents in the area” and police were asking parents and guardians to take their children home.

BBC News NI’s Dean McLaughlin, reporting from the area, said the police helicopter is monitoring the situation and a public announcement was made asking the crowd to disperse.

He added about 10 PSNI Land Rovers and police dogs were at the scene, while a small fire has been started on Nailors Row.

Up to 50 young people have been involved.

Some residents on Bishop Street have had to leave their homes.

Sinn Féin councillor Sandra Duffy described the attacks on police as a “disgrace” and appealed for those involved to stop.

“I am appealing for calm at this time, and I would urge other young people not to get caught up in this activity as it could have a negative impact on their future,” she said.

“These futile actions are wrong and they are not representative of this city.

“They are in stark contrast to the hugely positive work and positive community events taking place across the Bogside this week.”