A man is fighting for his life in hospital after being shot in the head as he waited for his food in a Chinese takeaway.
Police are treating the brutal attack as attempted murder.
It was one of two shootings that took place on a night of violence in north Belfast.
The victim of the second shooting is understood to have been left with injuries to both legs.
A ring of police checkpoints was set up for a time on routes around north and west Belfast last night following the two incidents.
The first shooting took place at 5.40pm when a man - named locally as Harry McMahon - was sitting waiting for his takeaway at the Joy Inn on Oldpark Road.
Police have now said they believe one man was involved in the shooting of the 52-year-old. The attack is being treated as attempted murder.
One eyewitness who lives in one of the houses opposite described hearing a gunshot, then looking out the window and seeing a man slumped over in the shop.
There were frantic efforts to save his life before the ambulance crew arrived and transported him to hospital.
He is believed to have undergone emergency surgery late last night. The Belfast Health Trust said it could not confirm what his condition was on request of the family.
A section of the Crumlin Road was cordoned off for most of yesterday evening by the PSNI as officers carried out investigations into the incident.
Forensic officers examined the inside of the Chinese takeaway where the attack had happened.
A getaway car used by the attackers was dumped and partially burnt out less than a mile away.
The blue-coloured Vauxhall Astra was found on Torrens Gardens. This street was also cordoned off by the PSNI as forensic teams moved in.
PSNI detective chief inspector Alan Dickson said: "We are currently treating this as attempted murder and are appealing for witnesses. We believe this man drove to the fast food outlet in his van and parked outside. He was shot once in the head whilst inside the premises.
"From the information we have established so far we understand that one man was involved. He made off in a blue coloured Vauxhall Astra estate car, vehicle registration number ANZ 5590, which was later found on fire in Torrens Gardens a few minutes later.
"At this stage we have not yet established a motive for this attack but let me be clear, this type of criminality has no place in society.
"At this stage of our investigation we do not believe this to be linked to the shooting incident in the New Lodge area which occurred just over two hours after this attack but we are appealing for information on both incidents.
"We are particularly keen to hear from anyone who may have been in the Oldpark Road area around 5.35pm and who may have witnessed the shooting or any suspicious activity prior to it. We are also keen to hear from anyone who may been in the area of Torrens Gardens when the vehicle was set alight.
The shooting was last night being linked to a feud between dissident republicans.
North Belfast MP Nigel Dodds said the community was deeply shocked at the attack and called for people to go to the police with any information.
"There is widespread shock at this shooting incident during which a man was shot in the head.
"Murderous attacks such as this are the last thing we want to see happening on the streets of north Belfast."
North Belfast SDLP MLA Alban Maginness also condemned the shooting.
"I'm sure I speak for the entire north Belfast community when I completely and utterly condemn the savage act of violence," he said.
"The brutal and public nature of this attempted murder is an indication of the barbaric mentality of the individual who carried it out.
"This kind of criminality has no place in modern society and is completely at odds with the values held by the north Belfast community.
"While I am unaware as to his current condition, I can only express my deepest sympathies for the victim's family who must be greatly distressed at this time."
PUP councillor for the Oldpark area, Julie-Anne Corr, described the night's events as "extremely worrying".
She said: "Punishment-style shootings and attempted murder are a worrying development and reek of the dark past we are working to overcome."
A second shooting took place in north Belfast just an hour after the first attack.
A man - believed to be in his 30s - was shot in both knees in the Victoria Parade area of the New Lodge at around 8pm in what police described as a paramilitary-style attack.
He was taken to hospital for treatment to his injuries which are not believed to be life-threatening. Inspector Murphy also appealed for information about this incident.