UK police closed the area around Big Ben in London on Saturday after a man holding a Palestinian flag climbed up the tower housing the famous clock and bell.
The man had ascended several metres (feet) and was perched barefoot on a ledge of the historic structure, whose official name is Elizabeth Tower, according to news agency AFP.
Crowds looked on from beyond a police cordon, while emergency vehicles were deployed in the area and Westminster Bridge was closed.
Police said they were first alerted “to a man climbing up the Elizabeth Tower at the Houses of Parliament” shortly after 07:00 GMT.
At around 10:00 GMT an emergency team used a fire truck lift and a megaphone to try to speak with the man.
But he was still there several hours later.
“Officers are at the scene working to bring the incident to a safe conclusion,” London’s Metropolitan Police force told AFP.
“They are being assisted by the London Fire Brigade and the London Ambulance Service.”
The protest came amid growing calls in the UK for the government to halt arms sales to Israel following the devastating war in Gaza, which has killed over 61,700 Palestinians – mostly women and children.
Activist groups have been staging high-profile demonstrations across the country, targeting arms factories and government buildings linked to the UK’s defence industry.