Police are appealing for witnesses after two knife crimes on the same day in Bradford.
At about 9.45pm on Thursday, a robber armed with a knife held up a shop in Huddersfield Road before fleeing with cash and cigarettes.
The man entered the convenience store and placed a note on the counter demanding cash and produced a knife.
He then grabbed a small amount of cash from the till and two packets of cigarettes before running out of the shop and along Huddersfield Road towards Low Moor.
Two staff members were left shaken by the incident, but otherwise unharmed.
The suspect was described as white, about 6ft tall and slim. He was wearing a blue jacket, a grey hooded top and had a scarf covering his face. He was also wearing black gloves, white trainers and a pair of dark glasses.
Police have now released a CCTV image of a man they would like to speak to in connection with the robbery.
Detectives are investigating whether the robbery is linked to three other crimes last month, where notes were produced to demand cash.
In a separate incident earlier that day, an armed would-be robber fled empty handed after passers-by intervened to help his victim.
Detectives are now appealing for anyone who saw the incident on Thursday to get in touch before the man strikes again.
A spokesman said: “At about 2.30pm on Thursday, a 25-year-old man was walking along New Hey Road in East Bowling, when he was approached by a man who made demands for his bag.
“There was a struggle and a knife was produced, before a number of other people intervened to help the victim, forcing the attacker to run off empty-handed down Bowling Hall Road.
“It is believed he got into a blue Seat Ibiza, driven by a second man, which then drove off.”
The victim suffered minor facial injuries.
Detective Inspector Neil Benstead, of Bradford CID, said: “This was a frightening attack which left the victim quite shaken.
“On this occasion nothing was stolen, but we need to catch this man responsible before he tries something similar.”
The suspect is described as white, about 6ft and of slim to medium build. He was wearing a black hooded top, black tracksuit bottoms and black trainers. The driver of the vehicle was described as black.
Anyone with information on either incident is asked to contact Bradford CID on 101 or Crimestoppers on 0800 555111.