A woman who was stabbed in an Aldi supermarket, in Skipton, North Yorkshire, has died.
The 30-year-old was attacked at the store in Keighley Road at about 15:30 GMT on Thursday.
Shoppers were left terrified, with one witness saying everyone "screamed and ran up and down". The witness also said she had "never been so scared".
A 44-year-old local man has been arrested on suspicion of murder, North Yorkshire Police said.
A force spokesman said: "The suspect was initially detained by brave members of staff and public, before he was arrested by officers who were quickly on scene.
"He was taken into custody on suspicion of attempted murder, but it has now turned into a murder investigation despite the efforts of medics to save the victim."
'Staff racing about'
He added that they were not in a position to identify the victim at this stage, but her family was being supported by specialist officers.
The store was busy with shoppers at the time, and one said: "I just saw the aftermath, I was so scared I ran off.
"All the staff were racing about," she said, adding police vans arrived on the scene within minutes.
In a statement released on Friday, Aldi said the store would be closed until further notice to allow police to carry out investigations.
A spokesperson said: "We are working with the police following an incident at our Skipton store."