There have been calls for political leadership after a series of incidents across the weekend, including pro-IRA chants at a concert in west Belfast.
The Wolfe Tones played their annual gig to close Féile an Phobail in west Belfast on Sunday evening.
The event saw the band lead thousands of spectators in the singing of the lyric, “Oh, ah, up the Ra” repeatedly.
There were also scenes of chanting at the unveiling of a mural of a burning police vehicle. A video which surfaced online of the unveiling of the mural includes chants of “Get the Brits out”.
Police have said they are aware of the mural.
There has also been condemnation following the emergence of a photograph which appears to show Larne Football Club player John Herron wearing a T-shirt bearing the slogan “Up The Ra”.
DUP East Antrim MLA Gordon Lyons described the picture as “abhorrent” while UUP MLA John Stewart said Herron should never play for the side again.
Larne Football Club said in a statement on Monday that Herron has been suspended with immediate effect and that an investigation into the incident is under way.
Meanwhile, there has been condemnation of the sale of Parachute Regiment and UVF flags on sale at a parade in Derry at the weekend.
Mickey McKinney, whose brother William was among those shot dead on Bloody Sunday, said he was deeply upset by the flags.
"It's offensive, not just to myself but the other families and the wounded," he said.
Mr McKinney, who works as a taxi driver, said he is hurt by the continued flying of Parachute Regiment flags in some parts of the city.
He called on councillors from all parties to condemn the selling of the flags.
"I know there is a police investigation. We await to see what happens there," he said.
Members of the British Army's Parachute Regiment opened fire on civil rights' demonstrators in Derry in 1972, killing 14 people.
In 2010, then British Prime Minister David Cameron issued a formal, state apology for the "unjustified and unjustifiable" killings on Bloody Sunday.
Thousands of people, including more than 135 bands, took part in Saturday's parade to mark the anniversary of the end of the Siege of Derry in August 1689.
The Apprentice Boys have been contacted for comment.
Derry City and Strabane area commander Chief Superintendent Ryan Henderson said police became aware on Saturday of concerns around a stall on Glendermott Road selling flags and other paraphernalia.
“Our officers attended the location where the stall was and gathered evidence and seized a number of items,” he said.
“Enquiries continue to establish if any criminal offences have been committed.”
DUP MLA Emma Little-Pengelly described scenes over the weekend as “deeply disappointing” and urged political leadership.
She has called for an urgent investigation around funding from public bodies for Féile an Phobail.
“They are young people, many of them born after the Belfast/Good Friday Agreement and yet we are seeing this type of glorification of terrorism which is absolutely unacceptable,” she told the BBC.
“Shouting about paramilitary organisations, talking about the things they’ve done in the past in such a way, celebrating that, glorifying that, that is never an acceptable form of cultural expression, regardless of whether that is the IRA or any other paramilitary organisation. We are in 2022, this is not the Northern Ireland that we need to be building.”
Ms Little-Pengelly said recent comments by Sinn Fein vice president Michelle O’Neill that there was no alternative to violence in the past, “was not leadership”.
“I am calling on all political leaders, political representatives from across all parties to say very clearly, and send a very clear message today that all glorification of terrorism is wrong, it has to be called out when it happens,” she added.
Alliance MP Stephen Farry described a “very worrying spate of sectarian incidents over the course of the summer from different sections of the community”.
“In particular, young people have been swept up into this,” he told the BBC.
“I think we’re seeing almost a casual sense of sectarianism.
“We have had a real spate of these incidents over the summer and particularly this weekend.
“It does point to the fact that 25 years on from the Good Friday Agreement we have to have that sober lesson that we as a society haven’t done enough in terms of reconciliation and building integration.
“Divisions are very stark still in our society.”
Féile an Phobail director Kevin Gamble said this year was the biggest yet, with around 100,000 people attending more than 350 events.
He pointed out that representatives from all communities were welcomed to various events, and said that no major internment bonfires took place in Belfast due to a dance music night put on by Féile to divert young people.
“The benefit of the absence of these unwanted bonfires on 8th August is significant, as well as the positive images emanating from the festival events showcasing Belfast in a positive light. There is also the considerable benefit to the city’s economy which the associated increase in visitor footfall and spending brings due to Feile,” he said.