A man believed to have been armed with a knife was tasered and arrested by police near the Houses of Parliament in London.
Footage on social media appeared to show the individual surrounded by armed officers.
A statement from the Metropolitan Police said a man was seen “behaving erratically” before the arrest.
A spokesperson for the force said: “At around 11.50am on Friday, October 21, a man was seen behaving erratically in the SW1 area.
“He was stopped by armed officers on Millbank.
“Police taser was discharged and the man was arrested on suspicion of possession of a bladed article. He has been taken into custody.
“There have been no reports of any injuries.”