Police believe the answers to solving the knife crime issue in Sheffield lies with those who carry weapons after a second man was stabbed to death in Sheffield in the space of 11 weeks.
Chief Supt Stuart Barton, district commander for Sheffield, was speaking after a 19-year-old man was stabbed to death on Tannery Close, Woodhouse, at around 11.30pm on Tuesday.
It comes just 11 weeks after dad-of-three Jarvin Blake was knifed to death in broad daylight on the streets of Burngreave and a 19-year-old man was stabbed on City Road on Monday.
Chief Supt Barton said: "When I woke up this morning and you see that a young man has tragically lost his life and probably not ten weeks ago I was sat in front of cameras and stood in front of microphones talking about the tragic loss of life of Jarvin Blake - it's a very difficult position to be in.
"But what I can say is we continue to do what we can to work with the people in schools, work within the city centre at nighttime operations but the answers to knife crime lay with the people that carry those knives.
"It's about friends, family, loved ones, telling them not to do it to put those away. Unfortunately, we then end up with the tragic circumstances like the two murders we are currently dealing with."
A 17-year-old girl and a 22-year-old man have been arrested on suspicion of murder and remain in police custody.
A huge police cordon also remains in place on Tannery Close and on Tannery Park, with crime scene investigators on the scene at around 1.30pm.
Chief Supt Barton added: "Knife crime is a huge concern to the force, it's a huge concern nationally not just to Sheffield. I was only sat with partners yesterday afternoon talking about how we are going to tackle knife crime, what can we do.
"We are currently working with consultants from Northern General Hospital to try and help us with expertise in this area of business. It's on the news not just in Sheffield but everywhere so it's something we continue to work on and will do over the coming months and years."
Chief Supt Barton said detectives were still working with the victim's family to establish the motive for the attack and asked anyone with any information to contact police or speak to officers at the scene.
He said: "There may be people that have seen something that they thought was insignificant last night but now realise that maybe I should pick up the phone and contact the police, which they can on 101, or through Crimestoppers.
"Or if they want they can just go forward there will be people on those cordons over the next 24 to 48 hours - speak to the officers concerned. Please don't sit on something that can help us."