The unborn child of a woman stabbed and killed in a broad-daylight attack on Sunday died with its mother, police have confirmed.
A 53-year-old man, arrested in the area shortly after the incident took place, is being held in police custody.
The woman, who was from Grimsby, was walking to work when she was stabbed in the back in an apparently motiveless attack.
She was taken to the Diana, Princess of Wales Hospital where she and her baby died.
Police said they were keen to speak to witnesses who may have seen the man arrested in the area.
The family of the victim were working with the police and would soon complete the official identification, police said. A post-mortem was due to be carried out on Monday afternoon.