Thursday will be a national day of mourning for those killed in the Charlie Hebdo attack in Paris, French President Francois Hollande said in a national address today.

The two gunmen believed to be responsible for the attack, which left 12 dead, were on the loose, French authorities said. Around France and the rest of Europe, thousands turned out for rallies Wednesday evening, expressing solidarity with the satirical magazine and the nation of France. The crowds pledged defiance to those behind the bloodshed.

People gather in a show of support for the shooting victims at Charlie Hebdo: http://t.co/8uyDOK57v2 (photos) pic.twitter.com/4AfS5gpbRj

— WSJ Photos (@WSJphotos) January 7, 2015

R.I.P. Ahmed Merabet, a French police officer, a Muslim, the first victim of #CharlieHebdo attack, pic.twitter.com/bMzZgpXuL7 via @Ironyisfunny8

— Steven Greenhouse (@greenhousenyt) January 8, 2015

Eiffel Tower plunged into darkness as France remembers victims of #CharlieHebdo attack. (@BBCBreaking) pic.twitter.com/56nr0WalDR

— Breaking News Feed (@PzFeed) January 8, 2015