At least four blast bombs have been thrown at police in east Belfast, it has been confirmed.
Several petrol bombs were also hurled after disturbances broke out in the Lower Newtownards Road area.
The Police Service of Northern Ireland (PSNI) said there were no reports of any injuries. At least one plastic bullet was fired and water cannon have been deployed to quell the disorder.
A PSNI spokeswoman said: "Police are currently dealing with public disorder in the Lower Newtownards Road area of east Belfast... At least four blast bombs and several petrol bombs have been thrown at police. There are no reports of any injuries at this stage. Water cannon has been deployed and one AEP (attenuated energy projectile) round has been fired by police. Police would appeal for calm in the area and would call on those with influence to do what they can to help restore calm."
It is the fourth consecutive night of trouble in parts of Belfast.
Earlier, a pipe bomb packed with nails was thrown towards police lines in north Belfast. The device was hurled from the nationalist Brompton Park area of Ardoyne and exploded after striking an armoured police vehicle just after 5pm. There were no reports of any injuries.
Stones and other missiles were thrown at PSNI lines by a hostile crowd of about 50 in the Broadway and Glenmachen Street areas of south Belfast. The Shore Road in north Belfast was closed near the Mount Vernon estate, due to a crowd gathering at the estate's entrance and there were also a number of road closures in Portadown, Co Armagh, due to the "build-up of crowds".
In Londonderry where around 90 loyalists took part in white line protests police seized around 20 paint bombs believed to have been stashed by local youths. Earlier Twaddell Avenue in north Belfast was blocked to traffic due to a large protest of several hundred people but has since reopened.
The loyalists protests have been staged across Northern Ireland in opposition to the Parades Commission's decision to ban last Friday's annual Twelfth parade past Ardoyne.
In a statement the PSNI later claimed the blast bombs were thrown by masked men in the Lower Newtownards Road area. "The blast bombs thrown in the east Belfast area earlier this evening were thrown by masked men from the area of Pitt Park at police lines on the Lower Newtownards Road," a spokesman said.