At least 100 people have been killed inside a Paris theatre where hostages were taken following a series of terror attacks across the French capital.
Security forces launched an assault on the Bataclan concert hall and killed at least two of the attackers.
One official described "carnage" inside the building, saying the attackers had tossed explosives at the hostages.
At least six attacks have been reported across Paris, including two suicide attacks and a bombing near the Stade de France stadium, where the national football side was playing a friendly match against Germany.
Officials said shots were also fired in at least two restaurants, with 11 people killed in the 10th arrondissement.
A Paris city hall spokesman said the latest death toll was at least 140 people, according to reports.
French president Francois Hollande said he was closing the country's borders and declaring a state of emergency.
Witnesses of the attack at the Bataclan described the scene as "carnage" with "blood everywhere".
Marc Coupris, 57, who had travelled to Paris to watch the concert, told the Guardian: "It was carnage. It looked like a battlefield, there was blood everywhere, there were bodies everywhere.
He added: "Eventually, when a few gendarmes came in slowly we began to look up and there was blood absolutely everywhere. The police told us to run."
Prime Minister David Cameron said he was "shocked" by the attacks and the UK "will do whatever we can to help."
The Foreign Office said it was in "close touch" with the French authorities and it was "urgently investigating" whether there were any British victims.
The attacks come after the Charlie Hebdo atrocity, which took place in January and saw 12 people killed after gunmen stormed the offices of the satirical magazine.