Detectives believe that a pipe bomb which was found in north Belfast had been thrown at a passing police vehicle.
The PSNI have launched an attempted murder investigation into the apparent bid to kill police officers.
The finger of suspicion will again point to dissident republicans, who have carried out such attacks in the past.
The viable device was found on North Queen Street on Tuesday morning – a long road leading from Tiger’s Bay south to the republican-dominated New Lodge and Carrick Hill districts, at the northern end of the city centre.
The discovery prompted a security alert and Army technical officers carried out a controlled explosion to make the bomb safe.
PSNI Detective Chief Inspector Peter Montgomery said: “It is now believed that this device was most likely thrown at a police vehicle the evening before.
“If this is an attack on police officers, we are very lucky that none of my colleagues or members of the public were injured.
“This incident also caused massive inconvenience, disruption and upset for the local community of north Belfast and I would like to reiterate our thanks to the members of the public for their patience and co-operation during the operation on Tuesday morning.”
Mr Montgomery appealed for anyone who noticed anything suspicious in the area to come forward.
He said he also wanted to speak to the driver of a white van seen in North Queen Street just before midnight on Monday.