The six people injured when a car ploughed into a group of people in the Boucher Road area of Belfast on Monday night were filming a new crime series for RTE 2.
At noon today two remain in a critical condition in the Royal Victoria Hospital following the incident at the junction of Falcon Road and Apollo Road at around 8.30pm.
A Belfast Trust spokesman said a male and a female were also in a stable condition in the same hospital.
A 24-year-old man was arrested at the scene but later released on bail pending further police inquiries.
No further details of the circumstances have been released, but it is understood that the car involved in the collision was not part of the filming project.
Television production crew staff and extras were among those injured.
A spokesperson for RTE said: “The TV crew were in the process of setting up equipment when the accident occurred at around 8.30pm.”
Northern Ireland Fire and Rescue Service said firefighters administered first aid and oxygen therapy to the casualties at the scene.
John McPoland of the NI Ambulance Service said ambulances were in attendance “within minutes” of the collision which was quickly declared to be a major incident.
“We had reports of a car going out of control [which] ploughed into a crowd of people,” he said.
“We attended with seven A&E ambulances, a number of officers and a number of rapid response paramedics and we have taken six people away from the scene.
“People have a mixture of injuries including fractures and facial injuries.”
Mr McPoland said it was an “extremely rare” occurrence for a major incident to be declared for a collision in the city.
“At that very moment I was under particular pressure to try and maintain cover in the city for other calls,” he said.
“We did respond in that hour to another 10 calls,” he told BBC Radio Ulster.
Two of the injured, a man and a woman, were discharged yesterday afternoon after spending the night in hospital.
A spokeswoman for RTE said yesterday: “RTE is aware of the incident where members of an independent production company filming in Belfast city last night were injured by a car.
“The programme they were working on at the time is an independently produced series commissioned by RTE television.”
The spokeswoman added: “The PSNI are currently investigating the incident. RTE cannot comment further at this time. Our thoughts are with those involved and their families.”
Injured man had five hour operation
The mother of one of the two people being treated in intensive care yesterday posted a message on Facebook to say her son had suffered head injuries and was on a ventilator following five hours in theatre.
Grosvenor Rugby player Paul Kennedy was also said to be unconscious and being treated for a broken leg.
The club posted a message wishing him “a very speedy recovery”.