A number of petrol bombs were discovered overnnight and two street surveillance cameras damaged in an interface area of east Belfast.
Police recovered 22 petrol and paint bombs after a search in the Strand Walk area of the nationalist Short Strand.
Closed circuit television cameras were also put out of operation in the nearby Madrid Street and Albertbridge areas.
Chief Inspector Mike Ellis of Mountpottinger Police Station appealed to all community leaders to use their influence to ease tensions in the run-up to the Twelfth of July Orange parades.
He said: "These cameras are part of an initiative to provide protection for the whole community and have been very successful in other parts of the city in tackling crime and criminality."
It is the second consecutive night that police have discovered materials used for rioting in the Short Strand area. Last night, officers found eight crates of empty bottles used for petrol bombs and a large bag of nuts, bolts and lead weights in the Clandeboye area.
The area has been the scene of violent clashes between nationalist and loyalist mobs in recent weeks. The damage to the CCTV cameras also comes the night after an installation which nationalists in north Belfast say is being used to spy upon them was fired at and had tyres burned around its base.
The security camera was installed by police in the Estoril Park area of Ardoyne.
A police spokeswoman says the equipment was found to have been hit by "high velocity gunfire".
That installation is close to the flashpoint Ardoyne shops area which Orangemen will pass during Friday's Twelfth of July celebrations.