24 hours in pictures

Bangkok, Thailand: Anti-government 'red shirt' protesters amass in front of their barricade Photograph: Vivek Prakash/Reuters London, UK: A seven-metre (23ft) long model of a sperm whale is hoisted into the main entrance of the Natural History Museum Photograph: Dan Kitwood/Getty Images Photograph: Dan Kitwood/guardian.co.uk Jerusalem: A projection of lights are seen over the walls of Jerusalem's Old City during an event to mark international Earth Day Photograph: Bernat Armangue/AP Photograph: Bernat Armangue/guardian.co.uk Bristol, UK: A police dog handler is reflected in the window of a restaurant while businessmen watch as minor scuffles break out close to the Arnolfini Gallery, the venue for the second live televised debate between the three leaders of Britain's main political parties Photograph: Adrian Dennis/AFP/Getty Photograph: Adrian Dennis/guardian.co.uk Iceland: The Northern Lights above the ash plume of the Eyjafjallajokull volcano Photograph: Lucas Jackson/Reuters Photograph: Lucas Jackson/guardian.co.uk Port-au-Prince, Haiti: A man stands on the remains of a home damaged in the January earthquake Photograph: Ramon Espinosa/AP Photograph: Ramon Espinosa/guardian.co.uk Gyegu, China: Ethnic Tibetans queue to receive aid in the wake of the earthquake in Yushu Photograph: Kevin Zhao/Reuters Photograph: Kevin Zhao/guardian.co.uk Kolkata, India: Labourers take a nap at Sealdhah rail station Photograph: Piyal Adhikary/EPA Photograph: Piyal Adhikary/guardian.co.uk Managua, Nicaragua: Sandinista National Liberation Front activists shoot homemade mortars outside the National Assembly Photograph: Elmer Martinez/AFP/Getty Images Photograph: Elmer Martinez/guardian.co.uk Riyadh, Saudi Arabia: A man looks towards the sky as a sandstorm hits the city Photograph: AFP/Getty Photograph: guardian.co.uk Lima, Peru: Birds fly in the Pantanos de Villa nature reserve Photograph: Martin Mejia/AP Photograph: Martin Mejia/guardian.co.uk Naidong County, China: Tibetan farmer Baima Jiumei Photograph: China Photos/Getty Images Photograph: China Photos/guardian.co.uk