Emergency services have found a man 'safe and well' who is believed to have jumped into the River Thames from Westminster Bridge, the Metropolitan Police said.
The incident happened as people gathered to hold a vigil to honour the victims of last Wednesday's London terror attack.
Scotland Yard said a response team was called to sighting of the man – reportedly in his mid-twenties – shortly before 11.30am on Wednesday.
Westminster Bridge was closed and London Fire Brigade said they searched the water as far as Lambeth Bridge.
Fire engines, police and rescue boats rushed to the scene after a member of the public reported the incident.
The man was was retrieved by a police boat and is now in NHS care.
MPS on the water said in a tweet: “Multi agency response to rescue a person who had jumped from #Westminster Bridge. Recovered safe and well by @TowerRNLI. Now in #NHS care.”
A Twitter user called Isa who said they were in an office overlooking the incident said: "Watching the scenes at Westminster Bridge atm (at the moment), it's reassuring to see how quickly and meticulously the emergency services have responded."
A minute's silence will be held at 2.40pm as part of the memorial marking one week since the Westminster attack. Police officers are set to form a human chain with members of the public.
A 29-year-old woman remains in a critical condition after she fell some 50 feet into the Thames from the bridge during the attack in which Khalid Masood drove into pedestrians.
