Officers seized an imitation firearm and arrested a man while responding to calls about a street dispute.
Police were called to Bar Lane, Basford, at around 4.40pm on Monday (6 June 2022), after receiving reports of a man carrying a gun and a knife.
It is alleged that the suspect pulled out the weapons during a disagreement with another man in the middle of the street minutes earlier.
Firearms officers attended the scene and carried out a search which led to the discovery of a suspected firearm and a knife.
The suspected firearm turned out to be a BB gun.
A 21-year-old man was arrested at the scene on suspicion of possession of a firearm with intent to cause fear or violence, affray, and possession of a bladed article.
He remains in police custody.
Detective Sergeant James Hirst, of Nottinghamshire Police, said: “As the public should be able to expect, our officers will always take immediate and robust action whenever we receive reports of a suspected firearm or knife being seen.
“This incident should serve as a warning to anyone who carries a weapon – and that includes those who choose to carry an imitation firearm – that we will treat reports of this nature extremely seriously to help keep people safe.
“Brandishing any kind of firearm in a public place is an incredibly serious offence and will always be met with swift action by Nottinghamshire Police.
“We have arrested a suspect as part of this investigation, but our enquiries remain ongoing, so we’d ask anyone who has any information that could assist us to get in touch with the police on 101, quoting incident 503 of 6 June 2022, or by calling Crimestoppers anonymously on 0800 555 111.”
