Several officers brandishing guns were seen taking down the individual over a suspected firearm incident.
The pack of officers were seen dealing with the suspect by City Wide Taxis at The Hard around 8.30pm.
Police were then seen speaking to and restraining two men by the entrance to Gunwharf Quays.
Hampshire Police has been contacted for more details.
Watch the video attached and see pictures from the scene below.
5. Armed police arrest male near Gunwharf Quays
Armed police arrest male near Gunwharf Quays over suspected firearm incident on Tuesday 18 February around 8pm Photo: Stu Vaizey
6. Armed police arrest male near Gunwharf Quays
Armed police arrest male near Gunwharf Quays over suspected firearm incident on Tuesday 18 February around 8pm Photo: Stu Vaizey
7. Armed police arrest male near Gunwharf Quays
Armed police arrest male near Gunwharf Quays over suspected firearm incident on Tuesday 18 February around 8pm Photo: Stu Vaizey
8. Armed police arrest male near Gunwharf Quays
Armed police arrest male near Gunwharf Quays over suspected firearm incident on Tuesday 18 February around 8pm Photo: Stu Vaizey