A 24-year-old man last night remained in a critical condition in the Royal Victoria Hospital after a serious assault in north Belfast.
He is understood to have sustained serious head injuries.
Four men were attacked at 4.50am yesterday by two men on the Antrim Road.
The three other attacked men did not need hospital treatment.
Two men – aged 31 and 23 – were later arrested.
The Antrim Road was closed between Willowbank Gardens and Hopefield Avenue until yesterday afternoon.
Forensic teams combed the scene of the assault before the road was reopened.
Appealing for information, Detective Chief Inspector Alan Little said: “Anyone with any information about this incident is asked to contact us in CID at Antrim Road Police Station on 0845 600 8000.”
Last night SDLP MLA for North Belfast Alban Maginness said the assault is “quite frightening”.
“This was a shocking and frightening event which seems to have been a very organised attack,” he said.
“There were four men targeted, but one got the worst beating.
“Obviously the intent was to cause serious injury.
“This was a deliberate attack and it is frightening for everyone living in the area.
“It is totally unacceptable.
“One hopes that this young man will recover quickly from what seems to be a very serious injury to his head.”
SDLP councillor for the area Patrick Convery also condemned the assault.
Speaking after having raised the issue with local police commanders, Councillor Convery said: “This appears to have been a particularly vicious attack in the early hours of this morning.
“According to early reports a group of four men were assaulted by two others at around 4.50am.
“This kind of savage attack is completely unacceptable.”
He said his “thoughts and prayers are with one of the victims who has been rushed to hospital and is in a critical condition”.
“No family should wake up to a knock on the door by police telling them that their son is lying in a critical condition in hospital after being brutally beaten,” he added.
“Those who are behind this callous attack are beneath contempt and will be rejected by this community.
“I would urge anyone who may have heard or seen anything suspicious to contact the PSNI at Antrim Road Police Station and help to bring these thugs to justice.”
UUP Alderman David Browne condemned the assault.
“Anyone with any information should go straight to the police,” he said.
“It brings back memories of the attack on Thomas Devlin, although he was much younger.
“If it is an attack between two rival groups or a sectarian attack, no matter what is behind it, it is wrong.”
The MP for North Belfast last night slammed the serious attack which left a 24-year-old man fighting for his life in Belfast.
DUP MP Nigel Dodds said: “I am very shocked at the vicious and callour nature of this attack which has resulted in very serious injuries.
“Anyone with information should help the police in building a case against those responsible.
“Those who carry out such attacks deserve to be locked up and I know that the entire community will deplore what has happened.”
There was much sympathy on Twitter yesterday over the attack.
“Awful news of the assault on the Antrim Road this morning,” said one tweeter. “Hope the victims recover and the police catch the thugs behind it.”
Another said: “Hoping the fella pulls through. The actual situation seems very confusing with different rumours.”