Armed police swooped on a house in Springburn in front of shocked neighbours.
Unmarked police cars sped to Galloway Street, in the Springburn area of Glasgow, at 11.45am on Tuesday morning.
Neighbours watched as a team of armed officers laid siege to a property on the street and pointed guns at the windows.
Four men were arrested and led away from the property.
One witness told the Record: "Three unmarked police cars flew past us and a team of armed officers got out.
"Officers tackled and arrested one guy and then stood guard at the house pointing guns up at the window."
Police remain on the scene guarding the entrance to the property.
It is unknown what the nature of the operation is.
A Police Scotland spokesperson said: "Four men have been arrested following an operation involving armed officers at an address in Galloway Street in Springburn, on Tuesday, May 28.
"Officers remain at the scene and enquiries are continuing."
