Thugs wearing Balaclavas left a 26-year-old man needing hospital treatment after a brutal attack in an alleyway.
Detectives are investigating after the gang of three or four males struck at about 7.30pm on Sunday in Widnes.
Cheshire police said the victim was walking down an alley between Kingsway and Sharp Street when the group attacked.
He suffered a "serious" facial injury and was taken to hospital by ambulance.
The victim received treatment and has been discharged.
Police said the attackers were wearing dark clothes and had their faces covered with masks and balaclavas.
Enquiries are ongoing.
Detectives from Cheshire police have urged witnesses and anyone with anyone who may have information that may assist the investigation to make contact.
They also want to hear from anyone who may know the offenders' identities, or have CCTV or dashcam footage.
Detective Constable Gary McClatchey, of Widnes CID, said: "This was a terrifying incident that left the victim with a serious facial injury and extremely shaken up.
"I would like to reassure residents that this appears to be an isolated incident and we are determined to establish the identities of those responsible for the unprovoked assault and bring them to justice.
"As part of our enquiries we want to hear from anyone who was in the area that night and believes they may have seen something relevant to our investigation.
"We also want to speak to anyone who thinks they may know who the offenders are, or have footage of them."
Anyone with information or CCTV or dashcam footage that could help the ongoing investigation should call Cheshire Constabulary on 101, quoting IML 772051, give the details via www.cheshire.police.uk or contact Crimestoppers anonymously on 0800 555 111.
