At approximately, 2.10pm on Wednesday, 26 May, police officers on patrol in Rushey Green, SE6 identified a man and woman who they believed to be in possession of a firearm.
Specialist firearms officers were deployed to the scene. The man and woman were detained and an item believed to be an imitation firearm was recovered.
They were both arrested on suspicion of being in possession of a firearm in a public place.
No firearms were discharged during the incident and it is not being treated as terror-related.
Police are not looking for any further suspects and there is no risk to the public.