Roads around the Palace of Westminster in London were closed on Saturday as emergency services tried to reach a man who climbed the Big Ben tower holding a Palestinian flag.
Photos show the barefoot man, who appeared to be staging a protest, standing on a ledge several metres (yards) up Elizabeth Tower, which houses Big Ben.
Officials said tours of the Houses of Parliament were cancelled because of the incident.
Westminster Bridge and a nearby street were closed for much of Saturday and several emergency services vehicles were at the scene as crowds looked on from behind a police cordon.
At least nine emergency service vehicles lined Bridge Street in central London as crowds looked on from beyond a police cordon.
Three emergency personnel were lifted several metres up on a fire brigade aerial ladder platform at around 10:00 GMT, with one person using a megaphone to speak to the man on the ledge.
The incident began when the man got into the grounds of Parliament, walked up some steps, quickly climbed onto a railing, and up the side of Elizabeth Tower.
