A manhunt is underway for a black male in his late teens to early 20s in connection with the fatal stabbing of a 16-year-old girl on a bus in Birmingham.

Police say a male originally arrested on Lower Temple Street in the centre of Birmingham has been released. Police are appealing for witnesses in relation to the morning rush-hour stabbing on the A456 Hagley Road in Five Ways in the centre of Birmingham.

The 16-year-old old victim died at the scene and the family have been informed. A murder investigation has been launched and a manhunt is underway for the main suspect, described as a black male in his late teens to early 20s.

Police are looking into the possibility the suspect knew the girl but admitted investigations are still its in its "very early stages".

Det supt Richard Baker said: "This is a tragic case and the victim's family are devastated. Few of us can imagine what they are going through and we are working hard to indentify the offender which involves speaking to a large number of people who witnessed the attack.

"From their descriptions, we are keen to identify a young black man in dark clothing who was on the bus and seen fleeing from the area around the time of the murder.

"I would urge the public not to approach the man but to immediately dial 999. We have officers ready to respond immediately to sightings."

The suspect is described as a black man in his teens to early 20s, wearing dark coloured clothing. His jacket is thought to have a tiger's head or other large motif printed on the back. He may have been carrying a bag of some sort.

A West Midlands Police spokesman said: "At 7.37am today (Thursday 7 March) police received a call from a member of the public reporting that a passenger had been attacked.

"Officers and other emergency services were immediately dispatched but it was clear that nothing could be done to save the victim."

Police added that Hagley Road has now reopened after being closed following the attack.

West Midlands Ambulance Service added: West Midlands Ambulance Service can confirm it was called this morning to a medical emergency on board a bus in Hagley Road, Edgbaston shortly after 7.35am.

"A senior paramedic officer in a rapid response vehicle, two BASICS Emergency medics and two ambulance crews attended.

"One person was confirmed dead at the scene."

A National Express West Midlands Travel spokesman said: "We can confirm that a tragic incident took place on a number nine service on the Hagley Road this morning.

"Our thoughts and condolences are with the family of the person involved and we will offer all possible support to the police in their investigation into the matter."

The company are advising passengers to allow extra time for their journeys as the incident is effecting other services.

Witnesses are being urged to call the police on 101 or Crimestoppers on 0800 555 111.

In January, two Big issue sellers were fatally stabbed during evening rush-hour outside in Birmingham. One was stabbed outside a Sainsbury's supermarket in Martineau Place and the second near Boots in Union Street.