State of emergency has been declared across France after deadly attacks

A state of emergency has been declared across France after attacks on restaurants, a concert hall and a sports stadium in Paris killed at least 120 people, sowing widespread fear.

Four gunmen killed up to 80 young people attending a rock concert at the Bataclan music hall on Friday evening, city hall officials said. Heavily armed policemen eventually launched an assault on the building.

The gunmen detonated explosive belts and dozens of shocked survivors were rescued. The attackers were killed at the site and a manhunt is under way as a number of armed men are believed to be at large.

About 40 more people were killed in five other attacks in the Paris region, officials said, including an apparent double suicide bombing outside the national stadium Stade de France.

President Francois Hollande and the German foreign minister were watching a friendly football match between France and Germany there when the attacks occurred. Some 200 people were injured.

The coordinated assault came as France, a member of the US-led coalition waging air strikes against Islamic State of Iraq and the Levant (ISIL) fighters in Syria and Iraq, was on high alert for attacks.

There has been no claim of responsibility as of yet.

Paris Public Prosecutor Francois Molins said the death toll was at least 120. His spokeswoman said eight assailants had also died, seven of whom had blown themselves up with explosive belts at various locations, while one had been shot dead by police.

As France awakened on Saturday, security was tight across the capital, where about 1,500 soldiers were deployed, leave was cancelled for police personnel and hospitals recalled staff to cope with the casualties. 

Three restaurants and a shopping centre were also targeted in shooting attacks.

Reports also said that Paris has cancelled all public transportation services including the Metro on Saturday, as French newspapers decried a "War in the heart of Paris" with black mastheads.