Battle of Verdun marked by Francois Hollande and Angela Merkel 100 years on

French President Francois Hollande and German Chancellor Angela Merkel have marked 100 years since the Battle of Verdun.

The 10-month battle between February and December 1916 - the longest in the First World War - killed 163,000 French and 143,000 German soldiers. It wounded hundreds of thousands of others.