'Armed police' were called to the scene amid reports that a man was threatening a woman with a handgun.
Officers rushed to Ivy Lane in Bolton at around 4.35pm on August 14.
Police were responding to reports that a woman was being threatened 'by a man with a handgun', police have said.
Witnesses in the area reported seeing 'armed police' with three police 4x4s in the area.
The force says 'specialist officers' were deployed to deal with the incident.
An 'imitation firearm' was recovered by the officers.
A man was then detained under the Mental Health Act.
A spokesperson for Greater Manchester Police said: "Police were called shortly after 4.35pm on Saturday 14 August to a report of a man threatening a woman with a handgun on Ivy Lane, Bolton.
"Specialist officers attended and an imitation firearm was recovered.
"A man was detained under the Mental Health Act and a care plan has been put in place for his treatment."
