Armed police swooped after a man was seen wandering around the streets brandishing a gun.
Police confirmed they sent armed officers soon after reports "a man was brandishing a firearm in the street".
Witnesses said the man was wandering around Laird Street, Hoylake Road, Mercer Road and Lansdowne Road clearly holding a gun.
Residents said up to 12 police vehicles including armed officers were seen descending on the area around 7.30am today.
The suspected gunman was detained as part of the response.
One witness said: "So there's a lad roaming the streets with a gun, walked along Hoylake Road then up Mercer Road."
Other sightings included close to McColl's convenience store in Laird Street.
Officers responded quickly and detained the man shortly after, along with a gas powered BB gun.
A Merseyside Police spokeswoman said: "We have arrested a 25-year-old man in Birkenhead on suspicion of possession of a firearm.
"Officers were called to the area of Lansdowne Road this morning just after 7.30am, to reports a man was brandishing a firearm in the street. Officers responded quickly and detained the man shortly after."
The man has been arrested and taken to a police station for questioning.
If you have any information on firearms or where they are being stored contact Crimestoppers anonymously on 0800 555 111.
