A precautionary controlled explosion was carried out outside the palace, with the man held on suspicion of the possession of an offensive weapon, Metropolitan Police said.

Officers said that after a search, a knife was found on him but that he did not possess a gun.

Cordons were also put up after the man was found with a suspicious bag on him, police added. They have now been taken down.

He was detained as security preparations were under way for the King's coronation on Saturday.

Buckingham Palace confirmed neither the King or his wife, the Queen Consort, were at the palace at the time of the incident.

The man had allegedly approached the palace gates, threw the items over and then was arrested at around 7pm.

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The items "have been recovered and will be taken for specialist examination", the police said.

The event is not currently being treated as terror-related - instead it is understood to be an isolated mental health incident.

Metropolitan Police's Chief Superintendent Joseph McDonald said: "Officers worked immediately to detain the man and he has been taken into police custody.

"There have been no reports of any shots fired, or any injuries to officers or members of the public.

"Officers remain at the scene and further enquiries are ongoing."