A policeman stands outside the French embassy in Bogota, Colombia, November 14, 2015, following the deadly attacks in Paris. [Photo/Agencies]

Meanwhile, French President Francois Hollande called the coordinated gun attack and bombings an "act of war". He said: "We will lead the fight, and we will be ruthless."

Paris chief prosecutor Francois Molins told reporters that three teams of terrorists had staged the attacks, which targeted six sites including a concert hall, a major stadium and local restaurants.

"We have to find out where they came from... and how they were financed," he said. "We can say at this stage of the investigation there were probably three co-ordinated teams of terrorists behind this barbaric act."

Despite the recent surge of terrorist violence in the French capital, Paris is likely to press ahead with holding the climate change summit by the end of November 2015. No less than 100 world leaders including US President Barack Obama will partake in the summit, which runs for more than 10 days.

"Security at UN climate conferences is always tight but understandably it will be even tighter for Paris," Nick Nutall, spokesperson for the UN climate change secretariat in Bonn, told reporters.