The Tánaiste Simon Coveney has condemned violence in Co Derry on Monday night.
Police in Northern Ireland have started a full terrorist investigation after more than 40 petrol bombs were thrown at officers.
They also believe the New IRA is responsible for a bomb found in the Creggan area.
The Improvised Explosive Device was discovered in a parked vehicle in a residential area, close to many nearby houses.
Around 15 homes were evacuated while police were carried out the searches.
It happened just yards from the spot where journalist Lyra McKee was shot dead by dissident republicans in April.
That also followed the discovery of a mortar bomb in Strabane on Saturday.
Up to 80 police officers were conducting searches targeting the New IRA in Creggan Heights on Monday.
A group of up to 100 - many of them young and wearing masks covering their faces - then started throwing bricks and petrol bombs at patrol vans.
Two young people throwing the bombs suffered burn injuries, but no officers were hurt.
The PSNI believe the bomb found in a parked car was an attempt to kill police officers.
They believe the New IRA is responsible.
Tánaiste Simon Coveney has condemned the violence.
"Somebody could have been very seriously injured - have we learnt nothing from the killing of Lyra McKee?".
The area is still being patrolled - while some families who were forced to evacuate their homes on Monday are returning.
PSNI Assistant Chief Constable Mark Hamilton said people had gathered in the area and thrown over 40 petrol bombs.
He said the ‘Command Wire Improvised Explosive Device’ was found in a parked vehicle.
“We assess that this device was to be used against a police patrol in the Creggan area of the city,” he said.
“It is our assessment that the New IRA is responsible for this bomb. The bomb would have killed or maimed anyone near it when it detonated.”
He said the organisation intended to murder community police officers and had a “total disregard for the lives of everyone living in Creggan.”
“By bringing a viable bomb into the community, they have again proved that they have no regard for the lives of anyone living in Creggan,” he added.
“Once again they exploited some of the young people in the community to attack police and have brought disruption and misery to families.”
Sinn Fein MLA Karen Mullan said: “There is absolutely no justification for the actions which serve no purpose other than to put people at risk of serious harm and make the situation worse for local residents trying to get on with their lives, and they should stop now.”
SDLP leader Colum Eastwood said those attacking police officers were “inflicting damage on their own communities.”
“The brutal and sustained attack that officers have come under while trying to make our community safe is disgusting,” he said.
“Young people in this community are being manipulated and are risking their futures as a result.
“I would urge parents to contact their children and take them out of harm's way.
“People in this community will not be held to ransom by those who want to hold us all back.”
The device found in Strabane, Co Tyrone on Saturday has also been linked to the New IRA.
Police said the mortar was near a family home and was aimed at the local police station.
A 33-year-old man was arrested under terrorism legislation and has since been released.
Additional reporting: Jack Quann and Stephen Murphy