Dissident republicans have been blamed for a bomb left at a primary school in Northern Ireland.
The bomb, described by police as viable and significant, was an attempt to murder police, according to a senior officer.
It was found in an alleyway beside Holy Cross Boys' Primary School in Ardoyne, North Belfast, shortly before midnight on Saturday.
Around 20 homes in the Herbert Street area had to be evacuated while the bomb was dealt with and police said many of those woken up in the night were "very distressed young children".
A number of controlled explosions were carried out before the bomb was rendered safe and taken away for forensic examination.
PSNI Chief Superintendent Chris Noble said he was in no doubt that dissident republicans were behind the bomb and that their aim was to kill police officers.
"It's a very significant device more than capable of causing death and serious injury," he said.
"There's no doubt that device was there to try and kill community police officers on the beat in their local area, but also it was left in such a reckless manner and in such a reckless location that it would have undoubtedly led to the death or serious injury of a member of the public had it exploded anywhere near them."
He said the plot was provocative as the Holy Cross school name is synonymous with violent sectarian protests in 2001 and 2002 targeting Catholic schoolgirls.
Mr Noble appealed for anyone with information or who saw anything suspicious around the time the bomb was planted to contact police.
Sinn Fein MLA for the area Gerry Kelly condemned those who had left the bomb at the school, saying: "Those behind it have no regard whatsoever for this community and they need to end these futile acts."
Mark Lindsay, chairman of the Police Federation for Northern Ireland, said the criminals "didn't care if passers-by or children out playing in the area were caught up in an explosion".
"It was an entirely reckless act.
"Thankfully it was recovered and removed without being detonated."
Secretary of State James Brokenshire said he was "sickened" by the incident.
He added: "The consequences could have been utterly devastating and it shows (the terrorists) for what they really are.
"I am grateful to the emergency services for their work in keeping people safe."
Students are due to return to school on Monday, following their Easter break.