The group of four or five men armed with knives and crowbars gained entry to a house on Broadway and found two women and a girl inside last Sunday evening.
Two of the men then kept them isolated in a separate room whilst their accomplices searched the property for valuables.
Whilst the search was on-going, one of the men responsible for watching the occupants grabbed one of the women and removed an oxygen mask that she was wearing.
When the other woman attempted to intervene she was punched in the face and knocked to the ground.
The offenders, who are described as men wearing balaclavas and dark clothing, managed to flee the property with a quantity of jewellery.
Further enquiries have narrowed the time of the incident down to between 8:45pm and 9pm.
Detective Constable Zahir Hussain of GMP’s Oldham borough said: “This robbery left the people who were present at the time fearing for their lives. Thankfully nobody sustained serious injury; however it could easily have been a very different story.
“I would like to appeal to members of the public who have any information about what happened that night to please come forward.
“Broadway is a busy main road and it possible that people passing by at the time may have seen the offenders approaching the property or fleeing the scene.
“I would also ask that local businesses are on alert for anyone suspicious attempting to sell expensive jewellery, particularly a Rolex watch and gold rings.”
Anybody with information should contact police on 101, quoting incident number 2149 of 08/10/17, or the independent charity Crimestoppers, anonymously, on 0800 555 111.
