A number of warrants executed across the Corby area resulted in five arrests and a number of firearms seizures.
Five properties were raided on Thursday 13 October with more than 60 officers taking part in the joint Northamptonshire Police and East Midlands Special Operations Unit operation.
As a result, four men - three aged 21 and one aged 20, and a woman aged 35, were arrested for firearms, weapons and drugs offences.
Six firearms were also seized including a viable handgun and five dangerous air weapons. A number of edged weapons, ammunition and a small quantity of drugs were also taken away from the properties.
Superintendent Steve Freeman of Northamptonshire Police, said: “Thankfully, firearms are rare in this county and this country but when we receive intelligence that suggest their use, we act extremely quickly to mitigate any threat.
“I am really pleased with the results from this operation as crucially, it takes dangerous weapons out of the wrong hands and makes the people in this county safer as result.
“Searches will continue in the Corby area over the coming days as the investigation into those involved in the purchase, conversion and supply of these firearms continues.”