The woman was murdered in front of horrified onlookers in Bradford city centre at around 3.20pm yesterday.
Now cops have urged the public to report any sightings of 25-year-old Habibur Masum, who is wanted in connection with the attack.
Masum, from Oldham near Manchester, is described as an Asian man of slim build.
CCTV footage released by cops shows Masum wearing a duffle coat and tracksuits bottoms.
A witness also said Masum was wearing a grey hoodie with the hood up.
West Yorkshire Police said: “Detectives investigating the murder of a woman in Bradford have named a man who is wanted on suspicion of the offence.
“Police are appealing for members of the public to report any sightings of Habibur Masum, 25, who is from the Oldham area.
“He is wanted in connection with the fatal stabbing of a woman in the Westgate area of Bradford city centre yesterday afternoon.
“He is described as an Asian man, of slim build.
“He is pictured on CCTV wearing a duffle coat with three large horizontal lines of grey, white and black, light blue or grey tracksuit bottoms with a small black emblem on the left pocket and maroon trainers.
“A witness also reported seeing him wearing a grey hoodie with the hood up.
“He is believed to have links to the Burnley and Chester areas.”