A person holds a placard which reads “I am Charlie” during a minute of silence in Strasbourg for victims of the shooting at the Paris offices of weekly satirical newspaper Charlie Hebdo on Wednesday

A person holds a placard which reads “I am Charlie” during a minute of silence in Strasbourg January 8, 2015 for victims of the shooting at the Paris offices of weekly satirical newspaper Charlie Hebdo on Wednesday. French police extended a manhunt on Thursday for two brothers suspected of killing 12 people at a satirical magazine in Paris in a presumed Islamist militant strike that national leaders and allied states described as an assault on democracy. France began a day of mourning for the journalists and police officers shot dead on Wednesday morning by black-hooded gunmen using Kalashnikov assault rifles. French tricolour flags flew at half mast throughout the country. REUTERS/Vincent Kessler (FRANCE – Tags: CRIME LAW MEDIA)