Detectives from the Met’s Specialist Crime (Proactive) have carried out a joint operation with Thames Valley Police and Norfolk Constabulary.
The operation took place on Monday, 14 October as various locations in Aylesbury, Thetford and Newmarket
As a result seven people have been arrested for firearms and drugs offences.
A vehicle was stopped by armed officers in Newmarket and six firearms, together with ammunition and suspected class A drugs, were recovered; two people were arrested.
Armed officers from Thames Valley Police carried out a search of premises in Aylesbury and three people were arrested on suspicion of conspiring to import firearms.
Armed officers from Norfolk Constabulary carried out a stop of a vehicle in Thetford and found £9,000 in cash and arrested the male occupant for conspiracy to import/supply firearms.
A subsequent search of a house in Aylesbury resulted in the discovery of a handgun and the arrest of a woman who was at the address.
In all seven guns and a significant amount of suspected class A drugs have been seized.
All those arrested remain in custody.