Around 20 London statues have gas masks put on them in pollution protest

Two Greenpeace activists have scaled Nelson's Column in London to attach a gas mask to the famous statue to highlight air pollution in Britain.

Alison Garrigan, 29, and Luke Jones, 30, began climbing the 171ft (52m) central London landmark at 4am on Monday as part of a morning of stunts in protest at "dangerous" air quality levels.