Gallery: Images from shocking Paris attack
The attacks in Paris have met with international consternation and condemnation.
German Chancellor Angela Merkel declared herself "deeply distressed by the news and images that are reaching us from Paris”.
"I am shocked by events in Paris tonight. Our thoughts and prayers are with the French people," British Prime Minister David Cameron wrote on Twitter. "We will do whatever we can to help."
The European Union's main institutions also condemned the Paris attacks as "despicable acts" in a joint statement, expressing their solidarity with France.
Nato chief Jens Stoltenberg said he was "deeply shocked by the horrific terrorist attacks," adding: "We stand strong and united in the fight against terrorism. Terrorism will never defeat democracy."
A spokesperson for UN Secretary General Ban Ki-moon said: "The secretary-general condemns the despicable terrorist attacks carried out today in various locations in and around Paris."
From the White House, US President Barack Obama said the attacks were an "attack on humanity and the universal values we all share." US Secretary of State John Kerry called them "heinous, evil, vile acts”.
"Those of us who can must do everything in our power to fight back against what can only be considered an assault on our common humanity," he added.
Xi Jinping, president of China, said in a phone call to his French counterpart Francois Hollande that China "condemns in the strongest way this barbarous act" and said that he was prepared to join in any efforts to step up security and combat terrorism.
Australian Prime Minister Malcolm Turnbull said "The home of freedom has been assaulted by terrorists determined to attack and suppress freedom, not just in France, but throughout the world."
Brazilian President Dilma Rousseff said she was "shocked" by the attacks, which she described as an expression of "terrorist brutality."
"I express my rejection of violence and my solidarity with France's people and government," Rousseff posted on Twitter.
Argentinian President Cristina Fernandez de Kirchner also condemned on Twitter "the horror and the global tragedy of terrorism."
She added: "There is an urgent need to address on a global scale the issue of terrorism from a new, broader perspective, because otherwise we will not be able to feel safe anywhere."
Indian President Narendra Modi added his condolences calling the news of the attack "anguishing and dreadful."
"We are united with the people of France in this tragic hour," he said on Twitter.