Habibur Masum, 25, is wanted over the attack in the Westgate area of Bradford at 15:21 BST on Saturday.
The 27-year-old woman, who suffered multiple stab wounds, later died in hospital.
IMAGE SOURCE, WEST YORKSHIRE POLICE
Habibur Masum, 25, is wanted in connection with the fatal stabbing, police said
West Yorkshire Police confirmed she was with her baby at the time of the attack and told people not to approach Mr Masum.
The force said he was known to the victim but have not confirmed their relationship.
The force also said a knife was found at the scene but it is not clear if Mr Masum is armed.
He is from the Oldham area and described as Asian and of a slim build.
Mr Masum has been 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 hoody with the hood up after the incident on Westgate's junction with Drewton Road.
Police searching the scene, at Westgate's junction with Drewton Road.
Det Ch Insp Stacey Atkinson said: "We have had significant resources following up a number of lines of inquiry to locate Habibur Masum but at this time his whereabouts are unknown.
"I would urge anyone who does see him not to approach him but to call 999 immediately."
He is also believed to have links to the Burnley and Chester areas.
Det Ch Insp Atkinson said the death of a young woman in "such shocking circumstances" has caused "considerable concern" in the community, adding that residents could expect to see more police officers in Bradford.
The 27-year-old woman, who suffered multiple stab wounds, later died in hospital.
![Habibur Masum Habibur Masum](/forums/proxy.php?image=https%3A%2F%2Fichef.bbci.co.uk%2Fnews%2F976%2Fcpsprodpb%2F0ADB%2Fproduction%2F_133097720_untitled.jpg&hash=65438c2f1f3e986a3e4eb0592bacdc29)
Habibur Masum, 25, is wanted in connection with the fatal stabbing, police said
West Yorkshire Police confirmed she was with her baby at the time of the attack and told people not to approach Mr Masum.
The force said he was known to the victim but have not confirmed their relationship.
The force also said a knife was found at the scene but it is not clear if Mr Masum is armed.
He is from the Oldham area and described as Asian and of a slim build.
Mr Masum has been 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 hoody with the hood up after the incident on Westgate's junction with Drewton Road.
![Police searching the scene, at Westgate's junction with Drewton Road. Police searching the scene, at Westgate's junction with Drewton Road.](/forums/proxy.php?image=https%3A%2F%2Fichef.bbci.co.uk%2Fnews%2F976%2Fcpsprodpb%2F136DB%2Fproduction%2F_133097597_search1.jpg&hash=70c3121416fddaf4d1a67be9755e4290)
Police searching the scene, at Westgate's junction with Drewton Road.
Det Ch Insp Stacey Atkinson said: "We have had significant resources following up a number of lines of inquiry to locate Habibur Masum but at this time his whereabouts are unknown.
"I would urge anyone who does see him not to approach him but to call 999 immediately."
He is also believed to have links to the Burnley and Chester areas.
Det Ch Insp Atkinson said the death of a young woman in "such shocking circumstances" has caused "considerable concern" in the community, adding that residents could expect to see more police officers in Bradford.
![www.bbc.co.uk](/forums/proxy.php?image=https%3A%2F%2Fichef.bbci.co.uk%2Fnews%2F1024%2Fbranded_news%2F1A8F%2Fproduction%2F_133099760_bradfordsuspect-index.jpg&hash=af54bd71b45fb23247a1dd4ca3360018&return_error=1)
Bradford stabbing: Manhunt after mum pushing baby in pram killed
Police are searching for Habibur Masum after a woman was fatally stabbed in broad daylight.
www.bbc.co.uk