A man who sparked an alert after getting onto the roof at the Palace of Westminster has been arrested on suspicion of criminal damage and trespassing.
Emergency services including police negotiators, London Fire Brigade and London Ambulance Service were called when the 23-year-old was seen on the top of the building just after 9pm.
He was detained around eight hours later and taken to a police station.
In a statement Scotland Yard said: "At this stage it is too early to ascertain the reason as to why the man was trespassing on the roof."
The roof has been the scene of stunts by campaign groups in the past, including by protesters demonstrating against plans for a third runway at Heathrow Airport in 2008, and Greenpeace a year later.