The Northern Ireland Assembly is expected to condemn the latest attempts to derail the peace process after a car bomb attack and gun battle involving suspected dissident republicans.
The 400lb bomb partially exploded after a vehicle broke through a barrier outside the headquarters of the Northern Ireland Policing Board in Belfast.
Nobody was hurt, but two men were seen escaping from the area at Clarendon Dock on Saturday night.
In a separate incident, five men were arrested after police exchanged fire with suspected dissident republicans close to the border with the Republic in Co Fermanagh. The Police Service of Northern Ireland detained four in the area and gardai the other in Dooard, Co Leitrim.
Chief Constable Matt Baggott said Saturday's attacks were designed to derail political progress.
"We have said from day one that the terrorist situation is severe. We have substantial resources being put into investigating and thwarting these attacks," he said.
"This attack is an attack on the well-being of everybody in Northern Ireland. This is not about an attack on policing or the Policing Board, this is an attack on young people and young people's future."
A car was found burned out nearby in the staunchly republican New Lodge area of the city and police are investigating whether there was any link with the earlier attack.
The chief constable said that in Fermanagh his officers fired two warning shots, which are being investigated by Police Ombudsman Al Hutchinson. He said his officers had been fired at once during the exchange. It is understood the attack in Garrison was an attempt to kill a police officer who lived in the village, but it is believed the officer was not at home.
The ages of the detained men are 22, 26, 32 and 41. A suspect arrested by police in the Republic is aged 27.
