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The woman, believed to be in her 30s, was riding a bike along Harker Street about 2.30am when she was approached by two males and a female.

One of the males has produced a knife and made demands for her bike and personal belongings.

The victim was then slashed on her face, upper arms, torso, and neck before the offenders ran off on foot.

The woman managed to ride her bike about 50 meters then walked to Flemington Road where she flagged down a passer-by who called police.

She was transported to hospital where she remains in a critical but stable condition.

Investigators are yet to speak with the woman as she is undergoing emergency surgery.

Police are keen to speak to anyone who may have seen two male and a female, perceived to be of African appearance, that were in the vicinity of Harker Street about 2.30am this morning.

Anyone with information about the incident is urged to contact Crime Stoppers on 1800 333 000 or they can file a confidential report at www.crimestoppersvic.com.au.