A child holds a poster at a service in Londonderry, for those murdered at the Charlie Hebdo magazine offices in Paris

A child holds a poster at a service in Londonderry, for those murdered at the Charlie Hebdo magazine offices in Paris

A child holds a poster at a service in Londonderry, for those murdered at the Charlie Hebdo magazine offices in Paris, January 8, 2015. France began a day of mourning for the journalists and police officers shot dead on Wednesday morning by black-hooded gunmen who stormed the Paris offices of the weekly satirical magazine Charlie Hebdo, renowned for lampooning radical Islam. REUTERS/Cathal McNaughton (NORTHERN IRELAND – Tags: CRIME LAW POLITICS)