Police arrested four Extinction Rebellion activists after the Brazilian Embassy was daubed with red paint in a protest over the rights of indigenous people.
The activists blockaded the embassy, off Pall Mall, as part of international action targeting Brazilian embassies around the world.
Sian Vaughan, 54, a retired primary school headteacher, said: “We need everyone to know what’s going on in Brazil, and to tell the UK Government to act.
“If we close our eyes to the criminal destruction taking place, our children will pay the price.
"The climate crisis is global.”
Four people were arrested on suspicion of criminal damage, police said.
