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

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

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

Iceland: The Northern Lights above the ash plume of the Eyjafjallajokull volcano
Photograph: Lucas Jackson/Reuters

Port-au-Prince, Haiti: A man stands on the remains of a home damaged in the January earthquake
Photograph: Ramon Espinosa/AP

Gyegu, China: Ethnic Tibetans queue to receive aid in the wake of the earthquake in Yushu
Photograph: Kevin Zhao/Reuters

Kolkata, India: Labourers take a nap at Sealdhah rail station
Photograph: Piyal Adhikary/EPA

Managua, Nicaragua: Sandinista National Liberation Front activists shoot homemade mortars outside the National Assembly
Photograph: Elmer Martinez/AFP/Getty Images

Riyadh, Saudi Arabia: A man looks towards the sky as a sandstorm hits the city
Photograph: AFP/Getty

Lima, Peru: Birds fly in the Pantanos de Villa nature reserve
Photograph: Martin Mejia/AP

Naidong County, China: Tibetan farmer Baima Jiumei
Photograph: China Photos/Getty Images