A group of environmentalists has smeared St Mark’s Basilica in Venice with mud in protest at what they see as inadequate policies on climate change. Using fire extinguishers, the activists sprayed a mixture of mud, cocoa powder and water onto the façade and columns of the world-famous building on Thursday. Some tourists who happened to be present helped them. Initial reports suggest there was no permanent damage, and the dirt could be removed with cleaning agents. The mayor of the northern Italian city, Luigi Brugnaro, condemned the action. Six of the activists were taken into police custody. …