A man in his 30s has been arrested on suspicion of attempted murder after what police described as an “horrific, sustained knife attack” in north Belfast that left a man in his 40s in a serious condition in hospital.

The attack happened shortly after 10.30pm on Monday on Kinnaird Avenue in north Belfast, according to the Police Service of Northern Ireland. The victim suffered what Northern Ireland Secretary Hilary Benn told MPs were “very severe injuries”.

The case has rapidly become a political issue at Westminster and Stormont, with Prime Minister Sir Keir Starmer condemning the stabbing as “sickening” and ministers facing questions in the House of Commons over public safety, immigration enforcement and community cohesion.

Police said on Tuesday that the man in custody is Sudanese, correcting earlier information that had identified him as Somali. The PSNI said it was aware of “strong community concerns” after the “shocking attempted murder” and warned that inaccurate posts were circulating online, including claims about the victim’s condition.

“We can confirm that the injured man remains in a serious condition in hospital,” the force said. “As our investigation has progressed, we can also confirm that the man in custody is Sudanese and not Somalian, as initially believed.

“This is a fast-time investigation and we will continue to provide further updates to the public in due course.”

Speaking in an urgent question in the Commons on Tuesday, Benn said the whole House’s thoughts would be with the victim and his loved ones “at what must be a time of unimaginable distress”.

He added: “Shortly after 10:30pm last night, a man in his 40s was subjected to an horrific, sustained knife attack in a street in north Belfast. He is in hospital in a serious condition, having suffered very severe injuries.”

Benn said a man in his 30s had been arrested on suspicion of attempted murder and remained in police custody.

He also praised members of the public who intervened during the attack. “When confronted with scenes of terrifying violence,” he said, bystanders had stepped forward “at immense risk to their own safety”.

“To those individuals, I would like to say this: you showed the very best of humanity, and you have the profound gratitude of this entire house,” he told MPs.

The urgent question was requested by DUP leader Gavin Robinson, who asked the government to address the implications of the case for “public safety, immigration enforcement and community cohesion”.

Robinson told the Commons that footage of the incident had already been seen widely and said the events of Monday night would have “profound implications for community cohesion in this country”. He also said the suspect was in the UK on a five-year visa, although that detail has not been independently confirmed by the Home Office.

Calling for deportation if there is a conviction, Robinson said: “Having abused the privilege of our nation, the perpetrator living in the UK under a five year visa needs to be convicted and deported.”

In response, Benn said any foreign national who commits crimes “should be in no doubt of our determination to deport them”, but added that “we need to allow the criminal justice process to take place”.

He also defended the government’s record on migration, saying net migration was “down 82% from the peak under the previous government”, and repeated calls for calm to prevent “disorder in the streets”.

In Northern Ireland, Deputy First Minister Emma Little-Pengelly said she had spoken to the PSNI Chief Constable Jon Boutcher and urged “full and open communication with the public” about what she called a “deeply worrying and sickening situation”.

In an earlier statement, she described the stabbing as a “brutal act of violence” and urged calm “in what is clearly a tense and worrying situation”.

The North West Migrants Forum, which works with migrant communities across Northern Ireland and Ireland, also appealed against collective blame. In a statement, the charity said many people would feel “frightened, angry and in want of answers”, but added that its own members were also afraid about what the attack might mean for them.

“Northern Ireland knows well the danger of blaming an entire community for the deeds of an individual or small faction,” the group said.

The PSNI has not said publicly whether the victim and the suspect were known to each other, nor has it given any indication of a possible motive. No further details about the suspect’s immigration status have been formally confirmed by police.

The investigation remains ongoing.