A viable bomb discovered near a north Belfast primary school on Monday, was designed to maim and kill, the PSBI have said.
The BBC reports the device was found under a car on Ballymagarry Lane in the West of the city just before noon on Monday.
Police said the device, "could have been an under-car booby trap designed to kill and maim."
A number of homes were evacuated and four primary schools were instructed to keep children indoors during the security alert.
Army technical experts carried out two controlled explosions to make the bomb safe. No arrests have been made.
A police spokesman said: "Detectives from the PSNI's serious crime branch are investigating the circumstances surrounding the discovery of a viable explosive type device discovered in north Belfast earlier today.”
DUP MLA for Belfast North William Humphrey urged anyone with information on the attack to contact police.
He said: "Those responsible have been entirely reckless and did not care who suffered the consequences of their actions. We are indebted to the PSNI and Army bomb disposal officers who cleared this security alert.
"Those responsible for this deplorable device must be stopped before they succeed in their intention to cause death or serious injury. They must be given no support and no hiding place.
"I would urge anyone who has information which could assist the police to bring them to justice to pass that information on without delay."
According to the BBC, members of the PSNI and other potential targets have been warned to be on their guard.