Greater Manchester Police have launched a murder investigation and appealed for witnesses, after a man was killed in the city centre Getty

Police have launched a murder investigation after a 26-year-old man was stabbed to death in Manchester's city centre.

The man was discovered at around 3.25am on Sunday and was rushed to hospital in an ambulance. He later died as a result of his injuries. A 37-year-old man has been arrested on suspicion of murder.

Detective Superintendent Joanne Rawlinson of Greater Manchester Police appealed for eyewitnesses to come forward.

"Although one man has been arrested in connection with the murder, we still need to hear from anyone who was around the Charles Street area in the early hours of this morning or has any information which may assist us with our investigation," she said.

"We will have an increased police presence in the area as we continue our investigation and reassure local residents, so if you have any concerns or information you wish to provide, please come and speak to us.

"A young man has sadly died and our thoughts and deepest sympathies are with his relatives and friends," Rawlinson added.

"I cannot begin to imagine what they are going through. Specially-trained officers are offering them whatever support we can."

The death comes a day after a man was killed at a bus stop outside Waterloo Station in London – one of the capital's main transport hubs.

Paramedics found the man, in the 40s, with serious head injuries at around 2.45am on Saturday. He was pronounced dead at the scene.

A 29-year-old man was arrested nearby on suspicion of murder, and has been taken into custody at a south London police station. Scotland Yard said they are not looking for any other suspects in connection with the murder.

Detective Chief Inspector Diane Tudway, from the Homicide and Major Crime Command, said: "This is a very busy part of London frequented by both commuters and those on a night out.

"My team is keen to hear from anyone who was in the area or passing by at the time of this incident and may have witnessed what occurred or seen something that could assist the investigation.

"I would urge all witnesses and anyone with information to contact the incident room on 0208 721 4005 or call Crimestoppers anonymously on 0800 555 111."