A man has been arrested in Rochdale by the National Crime Agency (NCA) on suspicion of supplying firearms.
The arrest was made as part of a major investigation into the supply of firearms in the north of England.
Officers from the NCA's Armed Operations Unit detained the man in the Redfearn Wood area just after midnight on Thursday (April 23).
On Wednesday (April 22), three men were detained as armed officers moved in to stop a car in Tingley, West Yorkshire.
A handgun and ammunition was recovered from the scene.
The operation was assisted by officers from and Greater Manchester Police and West Yorkshire Police.
All four men are now in custody and are being questioned by NCA investigators on suspicion of being concerned in the supply of firearms.
NCA regional head of investigations Shane Williams said: “This was a significant operation which resulted in the recovery of a firearm and associated ammunition.
“We will continue to work closely with our partners to identify criminal organisations engaged in this type of activity as we have on this occasion with Greater Manchester and West Yorkshire Police.
“We know that criminal networks use firearms in their attempts to dominate communities through violence and intimidation.
"This is why cutting off that supply of guns is a priority for the NCA and the whole of UK law enforcement."
Superintendent Danny Inglis of GMP’s Serious Organised Crime Group said: “I’d like to thank our officers and partner agencies for this positive outcome and hope this reassures our residents in Rochdale that law enforcement is continuing to target those involved in serious crime.”
The NCA has asked anyone who has information about illegally held firearms or ammunition to contact the police.
Alternatively you can call Crimestoppers anonymously on 0800 555 111 or visit www.crimestoppers-uk.org.
