The break-in happened just after 3pm on Thursday, March 22, on Winton Street in the Lockwood area of Huddersfield.
West Yorkshire Police said the burglars made off with jewellery including watches, necklaces and rings.
They now believe the suspects to be three white males and one black or mixed race male, aged between 15-25.
Detective Constable Chris Eglen of Huddersfield CID, said: “I would like to speak to anyone who has any information about this incident or can assist with the identity of the males."
Anyone with information should call DC Eglan on 101, quoting crime reference number 13170044509.
Information can also be passed on via the West Yorkshire Police website ww.westyorkshire.police.uk/101LiveChat
Crimestoppers can be contacted anonymously on 0800 555111.