Police said they undertook an evidence-gathering operation in Portadown on Saturday afternoon as hundreds gather in protest over the NI Protocol.
Officers said that approximately 300 people took part in the processions, while a further 500 attended the protest.
Large crowds began arriving in the town crowd just before 3pm while a number of speakers addressed them at St Mark’s Church.
There was a large police presence in the area, including a police helicopter.
In a statement, Ch Insp Barney O’Connor said police were in attendance “at a number of un-notified processions in Portadown this afternoon which merged at West Street before walking together to join a protest in the centre of the town.
“The crowd was made up mostly of families and there were no issues.”
He added: “Organisers of parades/processions are required to give formal notification of their intentions and so a number of verbal and visual warnings were given out by police to participants this afternoon.
“An evidence-gathering operation was in place and we will now review all the footage gathered and consider any suspected breaches of the Public Processions (NI) Act 1998.”
Large loyalist/unionist rally opposing the Irish Sea Border taking place in Portadown this afternoon. The latest in a series of protest parades against the Northern Ireland Brexit arrangements. pic.twitter.com/mQKOlWKrSK
— Emma Vardy (@EmmaVardyTV) June 5, 2021
Sinn Féin MLA John O’Dowd has called on the PSNI to investigate alleged breaches of parade legislation.
“Several hundred protesters gathered in Portadown town centre today,” said the Upper Bann representative.
“An unnotified band parade also took place with the town centre basically closed down by the protest.
“While everyone has a right to peaceful protest there is an onus on everyone to act within the law.
“The Unionist strategy of marching people to the top of the hill only to abandon them has a long tradition of failure.
“Unionist leaders should pursue common cause with Irish nationalists and republicans instead of pursuing English nationalists who care not one jot for them.”