Cassie Hayes, 28, has been named as the woman who was viciously attacked inside TUI travel agents on Chapel Street, in Southport.
Her devastated partner, Leah Mcdonald, paid tribute to her on Facebook this afternoon, writing: "My absolute world I love you so so much have done since we first met i promise i will look after our girl the best i can."
Family and friends also paid tribute to her.
Rebecca Spencer posted online: "So sorry to hear this news, such a lovely person and will be sadly missed xx."
Another friend Helen Harper said she was "shocked and heartbroken".
Police put a cordon around a large area of the town centre and two air ambulances landed at the scene on Saturday afternoon.
Horrified witnesses said Cassie was knifed in the neck during the frenzied assault.
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FACEBOOK
An eyewitness told the Mirror Online: "I was walking past when they were rushing to get the woman into the ambulance.
"There was a lady from the travel agent shaking outside the shop, and lots of police around who had just arrived.
"I don’t think it was a shooting. I was further down Chapel Street and didn’t hear any gunshot."
She was transferred to Southport Hospital where she later died.
Police later confirmed a 30-year-old man is in custody.
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“We got quite a lot of different resources there, we’ve got air ambulances and ambulances”
North West Ambulance Service
Witness Rich Lawson, who was making a delivery to Vision Express when the attack happened, told the Liverpool Echo that staff were told to lock the doors to the opticians when police arrived.
He said: "When I got there they had locked all the doors. They let me in and locked it behind me and would not let me out.
"'I saw them bring a girl out on a stretcher and putting her into an ambulance.
"'She was covered up but I could see blood on her face. There was a lot of blood and she looked like she was unconscious. They rushed her into the ambulance.'
"I overheard a lady wearing a TUI uniform on the phone. She was shaking and said her throat was slit but whether that's true I don't know.
"I was in there for about 10 minutes and when I went back to my van and drove past the police riot van was up against the door and it looked like they were bringing a man out of the shop."
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A spokesman for Merseyside Police said: "The woman’s next of kin have been informed.
"A 30-year-old man from the Southport area has been arrested on suspicion of murder and is currently being held in custody.
"A male has been detained are the scene.
"It is believed that the incident was domestic-related."
Detectives are appealing for anyone with information to contact Merseyside Police on 101 quoting log 470 of 13t January or the Crimestoppers line anonymously on 0800 555 111.