The British government on Friday condemned the "intolerable violence" in Northern Ireland after a sixth night of rioting in Londonderry in which explosive devices were hurled at police officers.
The unrest in the province's second city, fomented by dissident Irish Catholic republicans, saw two explosive devices and 74 petrol bombs thrown at officers.
The five main parties across the political spectrum in Northern Ireland -- who have been unable to form an executive since January 2017 -- issued a rare joint statement condemning the attacks.
Police representatives said "terrorists" were spurring on children to "do their dirty work", launching missiles to lure officers into harm's way.
Tensions often flare up in Northern Ireland around July 12, when Protestants celebrate the 1690 victory of king William III of Orange over the deposed Catholic king James II at the Battle of the Boyne in 1690.
The province was devastated by three decades of sectarian violence which largely ended with the 1998 peace accords.
Karen Bradley, Britain's Northern Ireland minister, said in a statement that the "intolerable violence" was being perpetrated by "a small minority".
"The disorder in Derry/Londonderry last night, including targeted attacks on police vehicles and others, was completely unacceptable. These sustained attacks have been widely condemned and must end," she said.
The Police Federation, which represents rank-and-file officers, described the dissident republicans involved as a "pitiless, heartless bunch of cowards".
Federation chair Mark Lindsay urged mainstream Irish republicans -- committed to securing a united Ireland through purely peaceful means -- to take back the streets from the "gangsters".
"The terrorists who skulk in the shadows get children -- some no older than 12 -- to do their dirty work by firing petrol bombs, bricks and bottles at police lines," he said.
"Once the police engage, the bomber and gunman take control.
"This is child abuse. Young, vulnerable kids are encouraged to riot and cause mayhem so that the bomber and gunman can gain a better vantage position.
"It is sickening what they are doing."
Police said six automatic gunshots were fired at officers on Tuesday close to the famous Derry city walls.
On Wednesday, youths hurled missiles into a Protestant estate in the city.
Northern Ireland has been without a functioning executive for 18 months, with the main Protestant, pro-British DUP and Catholic, Irish republican Sinn Fein parties unable to resolve their differences.