Whitehall was briefly closed this morning by police after a “discarded item” was found near Downing Street.
The drama unfolded as people were ordered to evacuate while the object was examined.
It was later found to be non-suspicious, police said a short time later.
Witnesses said there was a “lot of police activity” as officers descended on the scene.
It is believed a bomb disposal robot was brought in by police.
In a brief statement the Met said: “Shortly before 11:00hrs on Wednesday, 8 September, officers on duty in the vicinity of Downing Street noticed a discarded item on Whitehall.
“A cordon has been put in place while an assessment is carried out to determine whether the item is suspicious.”
In a follow-up tweet a short time later, the force said: “The item has been assessed and is not suspicious. The cordon is being lifted.”
It is not currently known what the object that sparked the incident was, and the Met Police said it “wouldn’t comment” on this.
Pictures from the scene show officers manning a cordon on the famous stretch of road.
Sky News reporter Sarah Hajibagheri posted: “A lot of police activity down here – – press told to leave via the back gates immediately.”