A terrified mother and her children were held at gun-point in their Wembley home while four men ransacked their house.
The 57-year-old woman opened the door to the robbers on Friday at 11.15pm.
But she was forced back into the house and made to sit on the sofa with one of her sons while the men went upstairs and punched another in the face. A five-year-old child was also sleeping upstairs.
They then searched the house in North Circular Road and stole a plasma TV, three laptops, a passport, mobile phone and a suitcase.
All of the suspects are described as black, one was wearing a blue shiny jacket and one was wearing a green balaclava.
Detective Constable Brame, from the Priority Crime Unit, said: "This was a traumatic ordeal for the victims. I am appealing for anyone with any information regarding this incident or if they know the identity of the suspects to come forward."
Anyone with information should call 020 8733 3429 or call Crimestoppers anonymously on 0800 555 111.
