Police are investigating a parade commemorating Easter 1916 in Coalisland on Sunday.
Unionists complained after marchers wore paramilitary-style uniform at the ‘Unfinished Revolution’ parade, associated with dissident republicans.
About 50 people in paramilitary-style uniforms led the procession through the centre of Coalisland,.
Officers said they are examining “suspected breaches of Parades Commission determinations in Coalisland”.
In a statement, ACC Stephen Martin said: “In policing all events over the Easter weekend our overriding desire is to ensure that commemorative occasions, parades and protests pass off lawfully and peacefully.
“Our focus is on keeping communities safe and our job, with a few notable exceptions, has been made that much easier because of the responsible attitude of all parties concerned.
“We are however, investigating suspected breaches of Parades Commission determinations in Coalisland and un-notified processions in Ardoyne and Lurgan. We have gathered evidence at these events and will present reports to the Public Prosecution Service.”
It is understood that bus loads of people came from across Northern Ireland for the event, which started almost an hour later than scheduled.
During the speeches, Nuala Perry from the IRPWA blamed the delay on the PSNI, whom she said had tried to arrest a number of men in the colour party.
Wreaths were laid in honour of the Rising’s dead outside Patrick’s Hall after the wife of prominent republican Colin Duffy and IRPWA member, Mandy Duffy read a letter from prisoners.