At around 8.10pm, three male offenders threatened the occupants and demanded a watch, and other property.
No one was injured during the robbery, but they were left understandably shaken.
The offenders fled on foot with the stolen items.
They are described as being dressed all in black, with full face balaclavas with the eyes and mouth visible, average build, one being around 5ft 8, and one around 6ft and both spoke with Manchester accents.
Anyone who has any information about the robbery should call police on 0161 856 7528, quoting incident number 2522 of 13/02/21.
Details can also be passed on anonymously to the independent charity Crimestoppers on 0800 555 111.