Hundreds of people have gathered in Omagh, Co Tyrone in protest at the attempted murder of a senior police officer there earlier this week.
The crowd at the event, which was organised by trade unionists, was told there would be no going back to the violence of the past.
Detective Chief Inspector John Caldwell is fighting for his life in hospital having been shot at a sports complex on Wednesday night in front of his son.
Police have blamed the dissident republican group styling itself the New IRA.
Organiser Anton McCabe, from the Omagh Trades Union Council, said it was intended to give people a chance to show their abhorrence at the incident and opposition to those who wanted to return to violence.
"There must be no going back to the years of violence, fear and injustices," he said.
"The shooting of John Caldwell in front of children, was barbaric. It has traumatised the children who were there. It has opened up the trauma many carry from the past.
"A clear message has gone out today: no going back.
"Those who shot John Caldwell on Wednesday were in serious danger of lighting a fire that could burn us all, and let us be clear, the people of Omagh today have said no - no going back.
"We are standing not just in horror at what was done to John Caldwell, but standing here saying, 'Let us build a better society, of justice, peace and equality'."
Six men have been arrested by police and are being questioned about the shooting.
Detectives have been granted more time to question four of the suspects, aged 22, 38, 45 and 47.
The men, who are in custody in the Serious Crime Suite at Musgrave Police Station, can now be held until 10pm on Tuesday.
A fifth man, aged 43, was arrested yesterday and is also being held in Musgrave Serious Crime Suite.
A sixth man, aged 71, was arrested today and is being questioned by police.
Mr Caldwell had just finished training an Under-15 football team and was putting footballs in the boot of his car with his young son when he was approached by two gunmen.
They shot him, then followed him and shot him again as he lay on the ground.
He is in a critical condition in hospital after surgery for serious injuries.
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Patricia McKeown of Unison said peace in Northern Ireland was only born when "a massacre was perpetrated on the men, women and children of Omagh".
"Twenty-five years later, the attempt has been made again and your spirit and resolve is not broken," she said.
"The factions who rejected our peace agreement will not change the resolve of the people."
Padraig Mulholland of Nipsa said there are two Omaghs.
"There is the Omagh where this attack took place, but there is the positive Omagh; there is the Omagh that wants positive change and that was best represented by health and education workers who held another protest here earlier this week. They were here for young people, for working people, trying to fight for a better future," he said.
"No going back, let's fight for a better future for all."
A minute's silence was observed.
Ahead of the rally Mr Caldwell's football club held a march of solidarity in the village of Beragh, a few kilometres from Omagh.
He was coaching an U-15 team on behalf of Beragh Swifts when he was attacked.
Supporters were encouraged to attend in their club colours before heading on to the demonstration in Omagh.
Beragh Swifts chairman Richard Lyons said the community had gathered in support of their friend and for all the children that have been affected by the shooting.
"It's been a very difficult time for the club; it's been a very difficult time for the community," he said.
"John worked tirelessly for this club, he's no different to any other volunteer... the contribution that John gives to this club is phenomenal, and this is an unbelievably difficult time for us all".
Yesterday the leadership of Northern Ireland's five main parties joined PSNI Chief Constable Simon Byrne for a joint press conference to condemn the shooting and appeal for information.
Mr Byrne said he had spoken to Mr Caldwell's wife and son, who though badly shaken, wanted to thank those who had rendered first aid at the scene and to acknowledge the wider public outrage.
He added that he has also spoken to Garda Commissioner Drew Harris.
Mr Harris knows the injured officer from his years in the PSNI.
The commissioner has promised whatever garda support may be necessary to the PSNI investigation.
Additional reporting PA.
