Climate activists have gathered on Westminster Bridge "in mourning for the pollution of the river Thames". Extinction Rebellion protesters unfurled a banner which read "stop polluting our rivers".
Around 15 people, dressed all in red with their faces painted white, turned towards the river and stood motionless with their hands raised.
They were part of the Red Rebel Brigade, an international troupe whose members protest through performance art pieces.
The stunt was intended to "honour the water without which there is no life", organisers said. Other planned events included a march and "spiritual water ceremonies", Extinction Rebellion said.
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