A high-velocity rifle was used to spray up to 10 shots at a petrol station and injure a policeman in North Belfast, the PSNI's chief constable has said.
The community officer was shot three times in the arm and his body armour may have saved him from further harm, Police Service of Northern Ireland chief George Hamilton added.
Detectives believe rounds may have been fired from behind a fence across the road from the garage forecourt on the Crumlin Road on Sunday night as two officers emerged from the shop.
Dissident republicans have been blamed for the attack.
However, police in Belfast do not believe Northern Ireland's current political instability is related to last night's shooting.
Officers believe it was related to dissident terrorism, but say there has not been a rise in dissident terrorism since the power-sharing government collapsed this month.
The North's chief constable George Hamilton said: "The use of violence for any sort of political objective hasn't worked in the past, and it's certainly not going to work in the future.
"We will certainly not be deterred from our public service, from serving communities, from policing with the community.
"That's here to stay, we're resolute and detemined in that."
He said the victim was in a fairly serious condition and was injured on the right arm, suffering significant damage.
The chief constable said: "He is in good spirits. I never cease to be amazed by the bravery and the professionalism of police officers like him that I come across on a day-to-day basis."
He spent three hours in an operating theatre overnight and is expected to undergo more surgery in the days ahead.
Mr Hamilton added: "I would condemn this despicable attack, this act of complete recklessness as the filling station out on the Crumlin Road was riddled with high-velocity gunfire last night at 730 when people were going about their normal business, going to fill their cars up with fuel and buy groceries for children's lunches."
He added: "Our police officers are citizens in uniform. This officer was a member of the community.
"He was attacked but other members of the community were at massive risk as well and the people who did this did not care who they murdered last night, albeit it was clear the attack was aimed at the police officers on duty."
Police have appealed for anyone who saw an Audi saloon car in the area at the time to contact them.
Mr Hamilton said: "It is unlikely that shots were fired from the vehicle, this Audi saloon car, but we believe it was connected - perhaps as a getaway vehicle."
He said it was still a possibility that shots were fired from it but that was not the early indication.
"It is more likely that it was from some fencing across the road behind the garage."
He said political instability - Northern Ireland is facing fresh elections after the collapse of powersharing - did not have a significant effect.
He noted that the threat from dissident renegades has been severe since 2009.
"Within a couple of hundred yards of the site of last night's attack we have had previous attacks on police, whether that is gunfire or bombs being left for them, so I am not sure that the political instability is a huge factor at this stage."
A series of so-called punishment attacks in Belfast recently have been attributed to dissidents opposed to peace.
Mr Hamilton said: "These people who are responsible for this, they are the same groups of people who are involved in so-called punishment attacks on teenagers - child abuse that would be in our view.
"These are the same people who are taking it upon themselves to have some authority to license drug dealers.
"They are criminals, we don't want to legitimise them in any way."
He added: "The use of violence for any sort of political objective has not worked in the past and it is not going to work in the future."
Dissident republicans have attempted to kill several members of the security forces in Northern Ireland in recent years. Police, soldiers and prison officers have all died at their hands.
The attack comes amid warnings that a political vacuum has been created by the collapse of Stormont powersharing.
Northern Ireland is preparing for a March 2 poll.
Former deputy first minister Martin McGuinness resigned in protest over a botched green energy scheme which is predicted to leave taxpayers millions of pounds out of pocket.