Greenpeace protesters put a mask over Nelson's column in air pollution protest – video

Greenpeace protesters climb London's landmarks - including Nelson's column in Trafalgar Square - on Monday in protest over air pollution standards. Alison Garrigan and Luke Jones evaded security and scaled the 52-metre monument to Admiral Lord Nelson in central London after dawn, fitting a giant gas mask to Nelson's stone face to highlight dangerous levels of toxic air in the capital. The Shaftesbury memorial fountain and statues of Oliver Cromwell and Sir Winston Churchill were also fitted with masks

• Greenpeace activists climb Nelson's column in air pollution protest