Loyalists held a "constructive discussion" with senior PSNI officers last night to complain about so-called "two-tier policing".
Around 50 loyalists protested outside Musgrave Police Station in the centre of Belfast.
They were there to highlight what they claim is the political policing of loyalist parades.
Some held placards that read: "PSNI pepper spray: only to be used on Protestant, unionist, loyalist people (especially children)."
It follows a recent incident at a Junior Orange parade on the Ormeau Road in south Belfast in which an officer used CS spray.
During the trouble, two PSNI officers were injured and young children were affected by the CS spray. Police later charged a 26-year-old man with two counts of assault on police and disorderly behaviour.
The PSNI has said the matter could have been avoided had bandsmen "followed police directions" to keep clear of parked cars.
The Police Ombudsman is investigating.
A loyalist delegation, including Protestant Coalition chairman Robert McKee, met Superintendent Darrin Jones and Chief Inspector Robert Murdie last night. They handed in a letter of concern to one of the senior officers.
In a statement afterwards, Superintendent Jonathan Roberts said there had been "a constructive discussion around a number of issues relating to the parade on the Ormeau Road on Tuesday, 29 March."
It is understood the officer has not been suspended from duty.
The protesters claim that loyalist parades are subject to major restrictions that are enforced by police, but breaches at republican marches have been treated with leniency.
Beforehand, the Coalition said the protest was in response to "abuse carried out by officers towards South Belfast Young Conquerors Flute Band on their parade home on Easter Tuesday," adding: "Children as young as six years old were pepper sprayed and batoned. This is a two-tiered, politically-motivated policing system aimed at demonising those within the PUL community."