He waved the Palestinian flag from the top of London's iconic structure.

After scaling up the structure, he stayed there for more than 16 hours and refused to leave despite emergency service workers reaching him by climbing up in a crane.

The police arrested him once he reached the ground.

"This has been a protracted incident due to the specifics of where the man was located and the need to ensure the safety of our officers, the individual and the wider public,"  Westminister Police was quoted as saying by BBC.

"We worked with other agencies including the London Fire Brigade and deployed specialist officers to bring this incident to a close as quickly as possible whilst minimising risk to life," the police said.

The  Westminster Bridge was closed due to the incident.

Tours of the Parliamentary Estate were also cancelled in response, reported BBC.

Palestine

The man was seen waving Palestine flags when he was standing at the top of the structure.

In a video posted on Instagram, the man could be heard as saying by BBC: "If you come towards me you are putting me in danger and I will climb higher."

A small group of supporters came down to the spot and shouted "Free Palestine" and "You Are A Hero", media reports said.

The incident occurred amid the ongoing Israel-Gaza conflict.

They are currently heading to the second phase of the ceasefire.

Conservative MP reacts

Conservative Member of Parliament for Huntingdon Ben Obese-Jecty demanded an explanation of how the man could reach the top of the tower.

"Every day in Parliament I see dozens of armed police officers patrolling Portcullis House and the Parliamentary estate. Where were they today," he wrote on X.

"On Monday there needs to be a full explanation to MPs and staff as to how this protestor was able to evade security so easily," he said.