The near-simultaneous attacks in Paris that killed at least 127 people and wounded more than 180 were an "act of war" organised by Islamic State, says France's President Francois Hollande.

He said the attacks, carried out by eight gunmen and suicide bombers, were "organised and planned from outside".

Busy bars and restaurants, a music concert and a high-profile football match were all targeted.

Hollande has declared three days of national mourning.

He has raised the security threat level to its highest point, declared a nationwide state of emergency and vowed to wage a "merciless" fight against terrorists.

The night of violence unfolded soon after 20:00GMT as people were enjoying a Friday night out in the French capital.

At least one gunman opened fire on Le Carillon bar in the rue Alibert, not far from the Place de la Republique, before heading across the road to Le Petit Cambodge (Little Cambodia), killing at least 12 people.

"We heard the sound of guns, 30-second bursts. It was endless. We thought it was fireworks," Pierre Montfort, a resident living close to Le Petit Cambodge said.

A few streets away, another gunman then opened fire on diners sitting on the terrace of La Casa Nostra pizzeria in rue de la Fontaine au Roi.

Meanwhile, in the north of Paris, 80,000 people who had gathered to watch France play Germany at the Stade de France heard three explosions outside the stadium about half an hour after kick-off.

President Hollande was among the spectators and was whisked to safety after the first explosion. Three attackers were reportedly killed there.

By far the worst attack happened at the Bataclan concert hall, where at least 80 people were killed after gunmen stormed the venue.

US President Barack Obama spoke of "an outrageous attempt to terrorise innocent civilians".

UK Prime Minister David Cameron said he was shocked and pledged to do "whatever we can to help".

The Vatican called it "an attack on peace for all humanity" and said "a decisive, supportive response" was needed "on the part of all of us as we counter the spread of homicidal hatred in all its forms".

Attack sites:

La Belle Equipe, 92 rue de Charonne, 11th district - at least 19 dead in gun attacks

Le Carillon bar and Le Petit Cambodge restaurant at rue Alibert, 10th district - at least 12 dead in gun attacks

La Casa Nostra restaurant, 92 rue de la Fontaine au Roi, 11th district - at least 5 dead in gun attacks

Stade de France, St Denis, just north of Paris - explosions heard outside venue, three attackers dead

Bataclan concert venue, 50 boulevard Voltaire, 11th district - stormed by several gunmen, at least 80 dead