Bogus police officers handcuffed two people before robbing them of firearms and jewellery.
Four men purporting to be officers called at a home in Boggart Lane, Sowerby Bridge, at 4.45 pm on Tuesday saying they needed to search the premises.
They then forced their way into the property and the two occupants were handcuffed and the houme was systematically searched.
Licensed firearms - including a Remmington rifle similar to that pictured - ammunition, gold sovereign coins and a Rotary watch were taken.
“We would like to reassure the community we are doing all we can to trace the suspects and recover the stolen firearms,” said a police spokesman.
Three of the robbers are white and one is Afro-Caribbean, all are believed to be in their 30s.
They were wearing black stab vests with metal badges.
Detectives have carried out house-to-house inquiries and want anyone with information to contact then on 101 or Crimestoppers 0800 555 111.