One man has died and seven people have been injured following a "random" series of stabbings in Birmingham city centre.
Two of those people are seriously injured after what police have described as a "major incident" overnight - and a murder investigation has been launched.
Chief Superintendent Steve Graham from the West Midlands Police told a news conference today that one unknown male suspect is being sought but no arrests have been made.
He said that there is no suggestion of terrorism, gang involvement, that firearms were used or that the stabbings were a hate crime.
He described it as a "random attack with no clear motive" and said no links had been found between the victims.
Earlier, British police declared a major incident in Birmingham city centre after officers were called to reports of multiple stabbings overnight.
The first attack took place in Constitution Hill, to the north of the city centre before further attacks in Livery Street, Irving Street and Hurst Street as the suspect made his way south towards the Arcadian area.
The incidents took place between 12.30am and 2.20am.
Eyewitnesses reported as many as eight people were injured during what Mr Graham described as a "linked series" of incidents.
Police confirmed early this morning that a "major incident" had been declared and later said: "We can now confirm that we have launched a murder investigation following last night's events.
"A man has died and another man and a woman have suffered serious injuries. Five others have also been injured.
Mr Graham said "significant resources" were being used to track the suspect.
"Already we've got people going down drains, we've got that level of detailed searches taking place which will hopefully reassure the people that we are doing everything we can do to trace the offender."
West Midlands Ambulance Service spokesman Nathan Hudson said about "14 ambulances" were sent to Birmingham city centre from around midnight.
Seven patients were treated by ambulance staff, five of them were taken to the city's new Queen Elizabeth Hospital.
Mr Hudson said: "Three have suffered critical injuries and sadly one man had lost his life ... Two further patients were transported to Heartlands Hospital and an outpatient with minor injuries was not transported with ambulance assets."
Pictures show forensic tents have been erected in the area and armed police and large numbers of unarmed colleagues in the area.
Several yellow police evidence markers could be seen on the ground, some near to broken glass.
Police urged people to remain calm and stay away from the area as the response would be ongoing "for some time" and cordons were in place.
Reporting by IRN