A protest rally is to take place in Co Tyrone on Saturday morning, condemning the shooting of police officer John Caldwell.
The detective chief inspector remains critically ill after he was shot in front of his son at a sports complex in Omagh on Wednesday.
A fifth man was arrested on Friday in connection with the shooting.
Trade unions have organised today's rally, which will take place at 11.30am at Omagh Courthouse.
Secretary of the Omagh Trade Union Council Anton McCabe said that the protest will be a stand against the "barbaric" attack:
"We want to say, there can be no going back to the past of violence, fear and injustice," Mr McCabe said.
"We do not want the North to be dragged back into that."
On Friday, Chief Constable Simon Byrne said he had spoken to Mr Caldwell’s wife and son, who he said have been heavily affected by the incident, and they want to pass on their thanks both to first aiders at the scene, and for the outpouring of support across the community.
Assistant Chief Constable Mark McEwan also confirmed they are treating the attack as terrorist-related.
“Our primary line of inquiry is the New IRA,” he said.
Stormont’s political leaders met with the chief constable in the wake of the attack.
Sinn Fein vice president Michelle O’Neill, DUP leader Jeffrey Donaldson, Alliance deputy leader Stephen Farry, UUP leader Doug Beattie and SDLP leader Colum Eastwood met Mr Byrne at police headquarters in Belfast on Friday morning.
They then took part in a joint press conference with Mr Byrne, who hailed the importance of the act of political unity.
“We echo our thanks because it has rippled through the organisation about how important it is that we’re joined by the political leaders today at this unique time to show that we stand together and call out this outrage for what it is,” Mr Byrne said. - Additional reporting PA
