A bomb left left by dissident republicans outside the gates of a primary school in north Belfast could have killed or seriously injured children and police officers, a senior PSNI officer has said.

The viable device, described as “sizeable” by Chief Supt Chris Noble, was discovered by a passing police patrol near to Holy Cross Boys’ Primary School in the Ardoyne district shortly before midnight on Saturday.

He said it was an attempt by dissident republicans to kill police officers.

In a statement, British government Secretary of State James Brokenshire said: “I am sickened by this incident with dissident republican terrorists placing a bomb close to a primary school in north Belfast.

“This shows their wanton disregard for human life, potentially putting children in danger.

“The consequences could have been utterly devastating and it shows them for what they really are. I am grateful to the emergency services for their work in keeping people safe.”

The Police Federation for Northern Ireland (PFNI) similarly condemned those responsible.

Its chairman Mark Lindsay, said: “The people who did this wanted to murder or maim officers. They 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.

“This appears to have been a deadly, anti-personnel-type weapon. Thankfully, it was recovered and removed without being detonated.

“The attackers are terrorising people who live in the area and preventing them from getting on with their everyday lives.”

SDLP Cllr Paul McCusker, who visited the scene Sunday morning, said the discovery was “a chilling reminder that some people remain willing to murder and maim in our community”.

Sinn Féin MLA Gerry Kelly said 20 houses had to be evacuated overnight, adding those behind the attack “have no regard whatsoever for this community”.

“I welcome the fact that this device was found before it killed or injured somebody and anyone with information should bring it to the PSNI.”