A year after 'Je suis Charlie', a divided nation struggles

One year on, an anxious, fragmented France is paying tribute to the victims of the killings at Charlie Hebdo magazine, with old divisions made worse by what President Francois Hollande has called "a terrible year".

After the Islamist attacks that killed 17 last January at the satirical weekly and at a Jewish supermarket, the French rallied, marched and lit candles in emotional gatherings celebrated as "the spirit of January 11", the day 4 million took to the streets.

But cracks in that unity soon appeared and, a year later, after an even bloodier assault on Paris by another set of homegrown Islamists in November, politicians are embroiled in a bitter debate over homeland security, and the anti-immigrant National Front is stronger than ever.