Dissidents are being blamed for the brutal murder of a man in his own home in west Belfast on Thursday night.
The man, named locally as Joe Reilly (43), was shot a number of times by gunmen in his Glenwood Court home in the Poleglass area at around 8pm.
Within minutes a crowd had gathered at the house amid scenes of distress.
Officers from the PSNI's Serious Crime Branch have launched a murder investigation.
Detective Chief Inspector Peter Montgomery said the murder was "a cold-blooded, summary execution of a man in his own house."
He said: "At this early stage of my investigations I have no motive for this murder and I will keep an open mind as to why he was killed.
"I have two appeals - firstly, I understand three children were seen in the area as the gunmen ran away.
"I need to talk to these children and find out what they saw."
"Secondly I appeal for anyone who was in Glenwood Court and Glenwood Crescent before or after 8pm to come forward."
No group has yet claimed responsibility for the attack but speculation is mounting that the murder was carried out by dissident republicans.
One neighbour said his mother heard the gunfire and "thought it was fireworks".
He added: "This place is wild".
The incident comes just days after Peter Lagan (56) was shot six times in the legs in nearby Glenwood Drive after being abducted in Ardoyne. That attack was claimed by Oglaigh na hEireann in a statement.
Sinn Fein MLA Jennifer McCann described distraught scenes at the house last night as members of the victim's family tried to see him.
Local councillor Stephen Magennis said the family of the man who was shot dead, and the local community, were in shock at the murder.
"The people who did this need to get off the people's backs," he said.
"This community is very, very shocked at what has happened here tonight. The mood is very tense, very angry."
The west Belfast representative said that his heart went out to Mr Reilly's grieving family - especially his partner and teenage son.
Mr Magennis said that, coming just a few days after another paramilitary-style shooting in the same area, it looked like republican dissidents were responsible for last night's crime.
SDLP West Belfast MLA Alex Attwood added: "These savage assaults had no place in our past and have no place in our society today".
Anyone with information is asked to contact the PSNI on 101 or the anonymous charity Crimestoppers.