Protesters have blocked four bridges across London, preventing traffic from passing , as part of a so-called "rebellion day" to force action to stop climate change .

Westminster , Waterloo , Lambeth and Blackfriars bridges have been blocked since 10am, whereas Southwark Bridge was previously blocked but has since been re-opened according to Transport for London.

Police made more than 70 arrests under the obstruction of Highway Act and Bail Act offences and have criticised the environmental campaigners for impeding emergency vehicles and not engaging with them before the planned action.

Huge crowds of protestors block Westminster bridge

Supt Waheed Khan, spokesperson for the Met, said on Saturday afternoon (November 17): “The demonstration has been ongoing since 10am today.

"Despite calls from us to move towards Westminster Bridge where we can facilitate their protest, the demonstrators continue to block a further three bridges namely Waterloo, Lambeth and Blackfriars.

“The demonstration is having a direct impact on others across London who wish to go about their daily business – and the emergency services from using the bridges to travel around London.

Police with demonstrators on Westminster Bridge for protest called by Extinction Rebellion

"Given that the organisers failed to engage with police prior to the event, we were unable to work with them around their plan and to make considerations for other Londoners.

“So far we have made 45 arrests for offences under the obstruction of Highway Act and Bail Act offences.”

By 4pm, the total number of arrests hit more than 70, police confirmed.

This protest follows other days of action aimed at forcing the government to act to prevent further global warming.

On Wednesday, protesters glued themselves to the gates of Downing Street.

At the start of the week, activists blockaded the UK's energy department by chaining themselves together on the pavement.