The robbery happened at around 9.20pm yesterday (April 29) in Larkholme Parade, with the ordeal lasting around 10 minutes.
One of the men ordered the occupants into a bedroom while waving a metal bar.
The trio then pinched a safe containing a “quantity of cash”.
No arrests have been made.
DC Isobelle Garratt said: “This is a shocking incident which has left the victims extremely shaken.”
“We know this kind of incident will have shocked the community and we have increased patrols in the area.
“We are at the early stages of our inquiry and we are asking the public to get in touch if they saw any suspicious vehicles or individuals in the area at that time.”
The men were described as white, wearing beanie-style hats, and with Irish accents.
One of the men is thought to have been younger than the other two – possibly 18 or 19-years-old.
Anyone with information, CCTV or dashcam footage can contact police by calling 101, quoting log number 1424 of April 30.
Alternatively, independent charity Crimestoppers can be contacted anonymously on 0800 555111 or at crimestoppers-uk.org.
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