A gang of armed robbers who raided a house in Leeds are believed to be behind similar incidents in Bradford.
Five masked men wielding weapons including a sawn-off shotgun and knives stormed the property on Wooler Avenue, Beeston.
They threatened a 56-year-old man before stealing jewellery.
The incident came little more than an hour after four men forced their way into a house in Rockland Crescent, Clayton, Bradford, and demanded to know where one of the occupants was.
They searched the property before stealing a lady’s Michael Kors watch.
Then, 45 minutes after the Beeston robbery, three or four men carrying weapons got into a house in Broad Lane, Bradford, and ordered the occupants to sit down and be quiet.
They stole jewellery and cash before escaping.
The suspects are believed to be white men in their late teens or early twenties. All wore black balaclavas and black gloves.
It is thought they used a black Mitsubishi L200 or similar vehicle.
The incidents happened between 5.45pm and 7.45pm on December 12, but police are now appealing for information.
Det Insp Ryan Bragg, of Bradford District CID, said: “The descriptions of the males involved in these incidents lead us to believe that they may be linked, so we would appeal to anyone who might have seen anyone acting suspiciously in these areas around the stated times to get in touch.”
He added: “Police are focusing high-visibility patrols in these areas of Bradford and Leeds following these incidents, and we would urge anyone with any concerns to speak to our officers.”
Anyone with information is asked to contact Bradford District CID on 101 or Crimestoppers on 0800 555111.