The PSNI said it had recovered petrol bombs and paint bombs from the Kenilworth Place area in east Belfast.
The loyalist neighbourhood is not far from Pitt Park, which stands near to the interface with the republican Short Strand.
It followed two petrol bombs being thrown in the Newtownards Road area of east Belfast on the evening of Tuesday at around 10pm.
No damage was caused.
Local policing Chief Inspector David Moore called for calm to prevail as the marching season progresses.
He said: “Today I have spoken with community representatives from across east Belfast, they have condemned this type of behaviour.
“I would appeal for calm within the area over the coming weeks and remind young people there are consequences when you get involved in this type of behaviour.
“What might seem like fooling about can often result in a criminal record which can affect travel, education and employment opportunities in the future.
“I would urge parents to make sure they know where their children are and what they are doing and to talk to them about the danger of getting caught up in the moment and the possible outcomes they could face if they are found committing any offence.”