Police are appealing for information following an attempted robbery in Bradford.
At about 10.45 pm on Wednesday May 21 a group of about four or five men entered a convenience store in Wibsey Park Avenue and began shouting.
Following a brief altercation at the counter, the male shop assistant sounded the panic alarm and the men fled from the store.
The shop assistant followed the men out of the store briefly before returning to lock up.
He then noticed blood coming from his right hand and saw that part of his thumb had been severed.
He was taken to hospital for emergency surgery and is currently in a stable condition in hospital.
The suspects are described as Asian, in their mid to late teens, of skinny build and around six feet tall. They were wearing dark hooded tops with the hoods up and dark tracksuit bottoms.
They were last seen running down Wibsey Park Avenue towards Farfield Avenue.
Two were believed to be wearing face coverings.
Detective Chief Inspector Tony Nicholson, of Bradford District CID, said: “We would like to hear from anyone who saw a group of men acting suspiciously in Wibsey Park Avenue in the time leading up to, or just after this incident occurred.
“The shop assistant sustained a nasty injury to his thumb and we are keen to trace these men to prevent any similar incidents from occurring.
“Patrols have also been increased in the area to offer reassurance to residents.
“Anyone with information is asked to contact Bradford District CID on 101 or Crimestoppers anonymously on 0800 555111.”