Police have formally linked the murders of Sean Fox and Mark Hall, who were killed in west Belfast almost one year apart.
Sean Fox, 42, died after being shot multiple times inside the Donegal Celtic Sports and Social Club off the Suffolk Road on 2 October.
Mark Hall, 31, was shot dead at his family home in Rodney Drive on 18 December 2021.
Detectives believe the murders were carried out by the same two gunmen.
Det Sup Int Eamonn Corrigan, head of the PSNI’s Major Investigation Teams said: “It is now our assessment the murders were carried out by an organised group of criminals who operate like terrorists and who may be, or have been, members of terrorist organisations.”
He added that the police did not want to attribute the murders to a particular organisation at this time. However, he stated that the two deaths bore “the hallmarks of dissident republican killings”.
Police released new images taken from CCTV of both crime scenes, which “clearly shows they are the same two men”.
Det Sup Int Corrigan said there were a number of similarities in the two murders including the location of west Belfast as well as the brazen and reckless style of the shootings in public in broad daylight.
“It is clear the gunmen have an in-depth knowledge of these areas in west Belfast and felt comfortable carrying out these executions in front of a number of people and witnesses.” he said.
Police said Mr Fox was “singled out” as he socialised in a busy function room at the social club.
Det Sup Int Corrigan said the gunmen were inside the premises for approximately 21 seconds and fired 20 bullets.
At one point, both gunmen stood over Mr Fox shooting him, as he collapsed to the floor.
“Anyone in that room or indeed nearby, could have been killed or seriously injured,” he added.
The suspects travelled to and from the crime scene on bicycles between 14:20 and 14:30 on 2 October.
One gunman was riding a silver or light grey “generic mountain bike” with a plastic bag over the seat.
“He was wearing a light grey hoodie with distinctive three orange lines down the arms.
“He is carrying a dark black holdall, which I believe contained the guns,” said Det Sup Int Corrigan.
The other suspect used a “racer bike with a distinctive rear point to the saddle which appears to be a Fizik Arione”.
He was wearing a blue hoodie, dark-coloured bottoms and light grey gloves.
The same disregard for the public’s safety was shown during Mark Hall’s killing, police added.
The gunmen fired several shots into his mother’s home and fired directly at his sister as they fled.
An image of the taxi used by the gunmen to travel to the crime scene was also released.
“The taxi has never been recovered and I would appeal to anyone who has information on the car and its whereabouts to contact police,” added Det Sup Int Corrigan.
Detectives have conducted a number of searches and arrests this week in west Belfast in relation to both murders.
They appealed for anyone with information to contact them.