A 30-year-old man was slashed in the face and neck in Midlothian on Monday morning.
The man was cut several times by his attacker on the footpath at The Square in Danderhall.
He was taken to Edinburgh Royal Infirmary then to St John’s Hospital in Livingston for surgery.
A Lothian and Borders Police spokesman said: "This was a particularly violent attack that has resulted in the victim sustaining multiple slash wounds to his face and neck, for which he will have to undergo surgery.
"Anyone who was in the area of The Square in Danderhall in the early hours of yesterday morning, who either witnessed the assault or noticed any suspicious activity, should contact police immediately.
"Anyone else who has any other information that can assist our inquiries should also get in touch."
Anyone with any information can contact Lothian and Borders Police on 0131 311 3131, or Crimestoppers in confidence and complete anonymity on 0800 555 111.
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