Police have today appealed for anyone who was in the area where a young Sunderland man was fatally injured to contact them urgently.
The 18-year-old victim, named on social media and by people gathering at the scene this morning as Connor Brown, is believed to have been stabbed.
Today, an alleyway between The Borough pub and Gatsby's at Vine Place in the city centre remained cordoned off as police carried out investigations at the scene.
It is understood that CCTV footage from the bars has been examined by police.
Related: Sunderland murder probe: 18-year-old dies after being attacked in city centre
A man has been arrested and is helping Northumbria Police with their inquiries.
Senior investigating officer, Detective Chief Inspector John Bent, said: "One person remains in custody, but we do need anyone who witnessed the incident or who may have information to get in touch with Northumbria Police.
"We would encourage anyone who saw anything, was in the area at the time of the incident, or thinks they saw anything suspicious, to get in touch via 101,quoting log 124 24/02/19 or Crimestoppers anonymously on 0800 555 111."