An 18-year-old male has been charged with murder following the death of Hazem Ahmed Ghreir in Belfast city centre.
Mr Ghreir, who was in his 30s, died after being stabbed in Downshire Place/Great Victoria Street area around 10.45pm on Sunday.
Police said they are not treating the attack as a hate crime.
On Tuesday night, the detective inspector leading the investigation said he is continuing to appeal to anyone who was in the area at that time to contact police.
D/I Darren McCartney said: “I am particularly keen to speak to a man and his partner who attempted to assist Mr Ghreir following this attack.
“I would ask anyone who has any footage captured from the incident to get in touch with detectives by calling 101.”
The man who has been charged in due to appear in court in Belfast on Wednesday morning (June 7).