A stabbing in Sneinton less than 24 hours after a similar incident is also being treated as murder.
Police were called to an address on Mill View Close, at 4.20am on Sunday by paramedics.
A 38-year-old man was found with stab wounds to his chest and died of his injuries a short time later.
A murder inquiry has been launched and officers have cordoned off the area while their investigations continue.
Less than 24 hours earlier, at just after 6am on Saturday, police found a man fatally stabbed at West Walk, off Walker Street.
On Sunday police named this victim as 27-year-old Martin Maughan.
A 43-year-old man has been arrested on suspicion of murder and remains in police custody in connection with this incident.
No-one is believed to have been arrested in connection with the second attack, and police are yet to release the second victim’s name.
But Police said while both men knew each other, they are treating both killings as separate incidents.
Several people posted tributes to both men on Facebook and wrote of their shock.
Owais Mohyuddin wrote: “I couldn’t believe it, mortified and in absolute shock and then this morning I wake up to the sounds of police sirens and heavy police presence and my street being cordoned off due to a second murder, this time it was my neighbour the elder brother of a friend and class fellow of mine, all this taking place literally on my doorstep all in the space of 24 hours.
“What is going on in Sneinton? How many more lives are going to be taken before we wake up? This violence needs to stop.
“My thoughts go out to the family and loved ones.”
Sean Toner wrote: “I’m in total shock my heart goes out to the Maughan family such a tragic loss.
“My kids grew up playing football with the boys from a very young age. Martin had a heart of gold he was such a funny lad, they were all like my extended family I’m lost for words. R.I.P Martin god bless.”
Wayne Miller posted: “I’m getting sick and tired of hearing about stabbings in Sneinton, that’s Christmas ruined for two families why can’t ppl just behave themselves and stop causing misery for families it makes me sick to the stomach, make love not war, my thoughts go out to the families.”
Chief Inspector Mark Stanley, of Nottinghamshire Police, said although both men knew each other both murders are being treated as separate incidents.
He said: “Scenes have been established at both of the incidents to make sure all available evidence is secured and preserved.
“We have increased visible patrols in the local area to reassure the local community and to provide them with appropriate information as to what has happened.
“The early indications are that these incidents are confined to people who are known to each other and who were at addresses they were invited to.”
He added a 19-year-old man has been arrested on suspicion of murder in connection with Mr Maughan’s death. A 43-year-old, arrested earlier on suspicion of murder, is still in police custody.
Chief Insp Stanley added: “No other people are sought in relation to this incident.”
Anyone with any information about Sunday morning’s incident is asked to call Notts Police on 101, quoting incident number 174 of December 11 2016.
Those with information about the first incident should call the same number quoting incident number 219 of December 10 2016.
