CCTV images of three potential witnesses to the murder of an 18-year-old have been released.
Fahad Mohamed Nur died after he was found stabbed near Cathays railway station in Cardiff on Sunday 2 June.
The footage, released by South Wales Police, shows three men walking through the area close to the time of the stabbing.
Three men have been charged with Mr Nur's murder and are due to stand trial next month.
Det Ch Insp Mark O'Shea said the potential witnesses had not yet been identified "despite extensive inquiries".
"I must stress they are not under suspicion of any offence nor are they linked in any way to Fahad's death," he said.
Mr Nur, who was born in Mogadishu, Somalia, lived with his family in Cathays.