A teenage girl has been stabbed to death on a bus in Birmingham city centre.
The emergency services were called to the A456 Hagley Road, at its junction with Five Ways, at about 07:40 GMT.
Police have begun a murder inquiry and the victim's family are being informed.
Traffic queues are backing up for several miles along the Hagley Road, one of the major routes into the city centre. The road is due to be shut for most of the day.
Officers were alerted by a call from a member of the public to say a passenger had been attacked.
The outbound side of the Hagley Road and surrounding pavements are likely remain closed for the rest of the day, police said.
Drivers have reported traffic queues of about five miles backing up from Five Ways to where the Hagley Road meets the M5 at junction three.
Forensics officers have been seen going into the bus, which remains at a bus stop outside an office block on the outbound side of the road.
Pedestrians are having to walk around the office block to get past the police cordon.
A spokesman from National Express West Midlands said: "We can confirm that a tragic incident took place on a number 9 service 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 said eight of its bus services - 9, 120, 126, 127, 128, 129, 140 and 141 - were affected by the stabbing.
It said services were being diverted via Calthorpe Road, Westbourne Road, Harborne Road and Chad Road to a part of the Hagley Road from where they were able to continue on their normal routes.
The company urged passengers to allow extra time for their journeys.