Eiffel Tower goes dark as France mourns over 120 dead

Paris: The Eiffel Tower stood dark in a symbol of mourning last night as France struggled to absorb the deadliest violence on its soil since World War II: coordinated gun-and-suicide bombing attacks across Paris that left at least 129 people dead and 352 injured.

President Francois Hollande vowed that France would wage "merciless" war on the Islamic State group, which claimed responsibility for the mayhem, as investigators raced to track down their accomplices and uncovered possible links to networks in Belgium and Syria.

Paris prosecutor Francois Molins said three groups of attackers, including seven suicide bombers, carried out the "act of barbarism" that shattered a Parisian Friday night.

He said the attackers in the Bataclan concert hall, where 89 people died, mentioned Syria and Iraq during their rampage. Of the hundreds wounded in the six attacks, 99 were in critical condition.

Seven attackers launched gun attacks at Paris cafes, detonated suicide bombs near France's national stadium and killed hostages inside the concert venue during a show by an American rock band, an attack on the heart of the pulsing City of Light.

Ahsan Naeem, a 39-year-old filmmaker, said he's been to many of the places that were attacked Friday.

"I've seen dozens of gigs at the Bataclan. Eaten at the Petit Cambodge. Sat outside Le Carillon on so many nights," said Naeem, who has lived in Paris for seven years. "All those places will have been full of my people. My friends. My acquaintances."

Late yesterday, a crowd of up to 250 people gathered for an impromptu candlelight vigil at the Place de la Republique, the site of a massive demonstration in the wake of the Charlie Hebdo killings earlier this year.

Adrien Chambel, a 27-year-old law student, said the crowd was much sparser than in January. "You feel that people are petrified," Chambel said.

Hollande, who declared three days of national mourning and raised the nation's security to its highest level, called the carnage "an act of war that was prepared, organised, planned from abroad with internal help."

The president said France would increase its military efforts to crush IS. He said France, which is part of a US-led coalition bombing suspected IS targets in Syria and Iraq and also has troops fighting Islamic militants in Africa, "will be merciless toward the barbarians of Islamic State group."

The Islamic State group claimed responsibility in an online statement in Arabic and French circulated by supporters. It was not immediately possible to confirm the authenticity of the claim, which bore the group's logo and resembled previous verified statements from the group.