She was taken to hospital where she subsequently died of her injuries.
The victim is yet to be formally identified but is understood to be 27 years old.
Masum was 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.
Image: Police released a CCTV image of the suspect. Pic: West Yorkshire Police
A witness also reported seeing him wearing a grey hoodie with the hood up.
Sky News has spoken to a shopkeeper who said the victim was pushing a baby in a pram when she was attacked.
He ran over to try to help the woman.
“She was on the ground. I tried… there was me, and another guy, we tried. But looks like she was gone,” he said.
He said he saw the victim the morning she died, with her child.
“The child is very small. I think it must be two to four months, something like that,” he added.
“She was walking with them all the time.
“What is he going to do when he grows up without mother?”
Joanna Coates, a local resident, heard what she now believes was screaming from the attack, but hadn’t realised what was going on.
Speaking to Sky News, she said: “All I heard was screaming and shouting ‘get off’. It was that bad screaming even my daughter woke up and heard it. She’s 16.
“I thought it was people on drugs, fighting over the drugs, there’s screaming all the time round this area. If I knew I would’ve gone and helped her.”
She added she thought it was “disgusting” what had happened.
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Duncan Milwain, a curate (trainee vicar) at Bradford Cathedral, had just returned from a few days off when he heard the news.
He told Sky News: “As someone with a very young child myself, my initial thoughts and feelings are with that young baby.
“It’s tragic for the woman and her family, but for this child, long after we’ve all disappeared and the news has moved on and we’ve forgotten about this, that young baby will grow up motherless. That’s the tragedy here.”
Police encouraged the public not to approach Masum.
“A knife was recovered from the scene of the murder, but we cannot say if Habibur Masum is armed,” said Detective Chief Inspector Stacey Atkinson.
“If anyone has any information about his movements or whereabouts since 3.20pm on Saturday please contact police as a matter of urgency.”
Roman Lavrynovych appeared at Westminster Magistrates’ Court on Friday and was remanded in custody.
Officers from the Metropolitan Police’s Counter Terrorism Command led the investigation because of the connections to the prime minister.
Emergency services were called to a fire in the early hours of Monday at a house in Kentish Town, north London, where Sir Keir lived with his family before the election.
Crystal Palace are celebrating a historic win in the FA Cup after a 1-0 victory against Manchester City at Wembley.
It’s the south London club’s first major trophy – and third time lucky after losing two previous finals they have played in. The win also means Palace have qualified for next season’s Europa League.
Eberechi Eze put his side 1-0 up with the game’s only goal in the 16th minute.
Man City were given a chance to equalise when they were awarded a penalty in the 33rd minute, but Palace goalkeeper Dean Henderson – who had earlier escaped a red card for a handball outside the box – saved Omar Marmoush’s spot kick.
Image: Crystal Palace’s Eberechi Eze scores. Pic: PA
Image: Man City’s Omar Marmoush after his penalty was saved. Pic: PA
It briefly seemed the south London team had gone 2-0 up after a 58th-minute strike from Daniel Munoz but the goal was quickly ruled offside.
They then held onto their 1-0 lead until the final whistle, which came after an agonising 10 minutes of injury time.
Image: Dean Henderson dodged a red card and saved a penalty. Pic: PA
Oliver Glasner’s team were the underdogs despite Manchester City having had a difficult season in the Premier League.
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Pep Guardiola’s side also lost to their neighbours and rivals Manchester United in last year’s cup final.
‘It’s all about spirit’
Palace goalscorer Eze said he had “no words” as he celebrated with his team mates.
Image: Eze celebrates after the final whistle. Pic: PA
“I can only thank God,” he told ITV. “This is special, this is what dreams are made of, for this club as well. Who would have thought we could do it?
“We’ve made history today. The tactics were good but it’s all about spirit. That’s energy, that’s everyone fighting together and doing what we had to do today.”
This breaking news story is being updated and more details will be published shortly.