CCTV has been released after an aggravated burglary at a home in Chislehurst, Bromley.
Two suspects went to the front door of the house, whilst another two waited behind bushes earlier this month.
When no one answered the door the group went to the back of the house, where one of them smashed the patio door with a crowbar and the group entered.
An 11-year-old boy was dragged from a room into the hall, where the rest of his family were already held, The Metropolitan Police said.
An elderly man then had liquid squirted in his face by the group who were also armed with hammers. The family were then threatened with violence unless they revealed where their jewellery and money was.
Although the burglars took mobile phones away from family members, one was able to phone another member of their family who informed the police of the situation.
Once the suspects realised the police had been contacted, they filled up a bag with jewellry and it is thought left in a silver car.
The bag belonged to a teenage girl in the family who the suspects had dragged upstairs and demanded jewellery from.
Police believe the suspects have been behind several burglaries in the area and they have been described as white stocky men with Irish accents.
It is thought that they are in their mid-20s and during the incident they were wearing Converse shoes with baseball caps and jackets.
The Bromley Burglary Squad is urging anyone with information to come forward by calling 07795 334 919 or contacting 101.
You can also tweet @Metcc or call Crimestoppers anonymously on 0800 555 111.
See the footage below: