A man armed with a knife confronted two Ministry of Defence officers, police say.
A man has been arrested on suspicion of attempted murder after two Ministry of Defence Police Officers were confronted with a knife.
The incident happened at about 08:50 BST at Horse Guards Parade in Westminster, London.
A Taser was deployed and a 29-year-old man was restrained by officers, the Met Police said.
There were no reports of any injuries and the incident was not being treated as terror-related, the force said.
The man was also arrested on suspicion of possession of an offensive weapon and remains in custody.
Whitehall has been closed due to the incident.
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