Man climbs London's Big Ben tower, waves Palestinian flag

"Officers are at the scene working to bring the incident to a safe conclusion. They are being assisted by the London Fire Brigade and the London Ambulance Service," the spokesperson said.

At least nine emergency service vehicles lined Bridge Street in central London and crowds looked on from beyond a police cordon.

The London Ambulance added that it had sent an ambulance crew, an incident response officer, and members of its hazardous area response team (HART) to the scene, according to BBC.

At around 10:00 BST, three emergency personnel were lifted several metres up on a fire brigade aerial ladder platform, with one person using a megaphone to speak to the man on the ledge.

A spokesman for London Fire Brigade (LFB) said they were responding to the incident alongside the police, BBC reported.