The attacks in Paris come in a year which has seen France gripped by the threat of terrorism.
The developments brought back memories of January, when one of the world's great cities was brought to a standstill by Islamist extremists.
On that occasion the French capital was rocked first by the Charlie Hebdo atrocity, when 12 people were killed after gunmen stormed the offices of the satirical magazine.
The sense of panic heightened when there was a subsequent attack on a Kosher supermarket, and the incidents triggered worldwide outrage.
Since then there have been a number of more minor strikes or attempts. In one, three Americans and a Briton overpowered a heavily armed gunman on a train from Amsterdam to Paris.
The horrific scenes in the city on Friday night represent an escalation compared to the previous incidents.
It is believed that the reported death toll means it is the deadliest atrocity on French soil in recent times. In 1961 a train bombing killed 28 people.
Other bloody attacks in Europe have included the 7/7 attacks in London, in which 52 people were killed, in 2005.
The year before a series of explosions in Madrid killed 191 people.
The reports of mass casualty shootings is likely to increase the sense of alert in other cities, including London.
Security services and senior police in the UK have repeatedly highlighted the risk of a Mumbai-style roaming gun massacre.
Earlier this year police carried out a simulated terror attack in the capital to test the emergency response to such a strike.
