A customer killed inside a city centre bank has been named locally as restaurant owner Gurvinder Singh Johal.
Mr Johal had been at Lloyds in St Peter's Street, Derby, with the bank holiday takings from his Hen and Chickens Bar and Grill in Shelton Lock, a family friend said.
The father of three, known to his friends as Danny, was stabbed shortly before 14:30 BST on Tuesday and died at the scene, Derbyshire Police said.
A man in his 40s has been arrested on suspicion of murder, and another in his 30s on suspicion of assisting an offender.
Both remain in custody.
A cordon remains in place at the bank, although St Peter's Street has reopened to the public.
A family friend told the BBC that Mr Johal was "a smiler" and "a good friend".
He said Mr Johal had just returned to Derby from a family trip to India with his wife, children and extended family.
Supt Rebecca Webster said the victim's family had been informed.
She said: "For the family of the victim, we know that life will never be the same again, and our thoughts are with them as they begin to deal with their tragic loss.
"Those who witnessed the incident and offered first aid and tried to help at the scene will also be understandably devastated by what happened.
"And there will, of course, be the impact on the wider community from such a shocking event."
Lloyds has said it is "deeply saddened" by the incident, while Labour MPs Catherine Atkinson and Baggy Shanker, who represent Derby North and Derby South respectively, said in a statement: "This is a tragic and shocking incident. Violence has no place in our community."
Brad Worley, manager for St Peters Quarter Business Improvement District (BID), said rangers would remain in the area to provide support and assistance.