PARIS (CBSNewYork/AP)A series of attacks targeting young concert-goers, soccer fans and Parisians enjoying a Friday night out at popular nightspots killed at least 129 people in the deadliest violence to strike France since World War II.

President Francois Hollande said the terror group ISIS was behind the attacks, and pledged that France would stand firm against its foes.

A U.S. law enforcement official confirmed at least one American was killed in the attacks.

French natives living in New York felt heartache and disbelief Friday evening upon hearing of the attacks.

At the time of the attacks, some French natives had gathered at the Provence en Boîte restaurant, at 263 Smith St. in Carroll Gardens, Brooklyn, to watch the soccer match between France and Germany at the Stade de France and heard the explosion.

The NYPD stepped up security and deployed counterterrorism units to key landmarks in the city.

President Barack Obama, speaking to reporters in Washington, decried an “attack on all humanity,” calling the Paris violence an “outrageous attempt to terrorize innocent civilians” and vowing to do whatever it takes to help bring the perpetrators to justice.

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The worst carnage was at a concert hall hosting an American rock band, where scores of people were held hostage and attackers ended the standoff by detonating explosive belts. Police who stormed the building, killing at least one of the attackers, encountered a bloody scene of horror inside.

The assailants’ weapons were those of war: automatic rifles and suicide belts of explosives. The killing was indiscriminate, spread across a swath of the city, in at least six different sites. An ordinary Friday night in Paris transformed into a bloodbath. The word Parisians used over and over as they tried to make sense of the horror was “carnage.”

At the packed Bataclan concert hall in eastern Paris, the attackers opened fire on the crowd as American rock band Eagles of Death Metal performed. One witness told France Info radio he heard them yell “Allahu Akbar” — God is great in Arabic — as they started their killing spree and took hostages.

About a mile from there, attackers sprayed gunfire at the Belle Equipe bar, busy as ever on a Friday night with patrons unwinding from their week. One witness, also speaking to French radio, said the dead and wounded dropped “like flies” and that “there was blood everywhere. You feel very alone in moments like that.”

The preliminary death toll there appeared to be 18 dead, Paris prosecutor Francois Molins said. White sheets were laid over bodies.

To the north, loud explosions reverberated around the national stadium, packed with some 80,000 fans watching France beat Germany in a soccer exhibition match. One of the loud detonations in the chill air so startled French player Patrice Evra that he paused in mid-run, seemingly lost, and kicked away the ball.

A police union official, Gregory Goupil, said the two explosions were suicide attacks and a bombing that killed at least three people — near two of the entrances to the stadium and a McDonalds. The stadium was the first site targeted.

From there, the wave of killings quickly spread.

There were 14 dead on one street, five on another, Molins said. The spread of the killings added to the confusion and made a coherent picture slow to form. But the shock was instantaneous, as was the understanding that this was terror and killing on a scale unseen in Paris since World War II.

“The terrorists, the assassins, sprayed the outsides of several cafes with machine guns and went inside,” Cadot, the police chief, said. “So there were victims in terrible and atrocious states in numerous places.”

Pierre-Henri Lombard was dining in a restaurant in the trendy neighborhood when he heard sounds like the fireworks for France’s Bastille Day national holiday.

Then the panic began.

“Waiters went outside and said it was a shooting. We saw dozens of people rundown the street, a couple were bleeding,” he said.

As police, soldiers and the emergency services sprang into action, sirens wailing, helicopters whirring overhead, medical personnel started reporting for work of their own accord to help treat the injured. Five subway lines were shut down entirely, and Paris police told people to stay at home and avoid going out unless absolutely necessary.

At the Bataclan, police launched an assault to free hostages. Haggard-looking survivors were bused away.

At the stadium, fans streamed onto the pitch after the match, preferring the relative safety of inside of the stadium to the chaos outside. Police forensic officers dressed in white scoured the blast sites for evidence.

French President Francois Hollande was quickly evacuated from the stadium and soon after declared a state of emergency.

“This is a terrible ordeal that again assails us,” French President Hollande said in a nationally televised address. “We know where it comes from, who these criminals are, who these terrorists are.”

France had heightened security measures ahead of a major global climate conference that starts in two weeks, out of fear of violent protests and potential terrorist attacks. Hollande canceled a planned trip to this weekend’s G-20 summit in Turkey, which was to focus in large part on growing fears of terrorism carried out by Islamic extremists.

Emilio Macchio, from Ravenna, Italy, was at Le Carillon restaurant, one of the restaurants targeted, having a beer on the sidewalk, when the shooting started. He said he didn’t see any gunmen or victims, but hid behind a corner, then ran away.

“It sounded like fireworks,” he said.

France has been on edge since January, when Islamic extremists attacked the satirical newspaper Charlie Hebdo, which had run cartoons of the Prophet Muhammad, and a kosher grocery. Twenty people died, including the three attackers. The Charlie Hebdo attackers claimed links to extremists in Yemen, while the kosher market attacker claimed ties to the Islamic State group.

This time, they targeted young people enjoying a rock concert and ordinary city residents enjoying a Friday night out.

One of the targeted restaurants, Le Carillon, is in the same general neighborhood as the Charlie Hebdo offices, as is the Bataclan, among the best-known venues in eastern Paris, near the trendy Oberkampf area known for a vibrant nightlife. The California-based band Eagles of Death Metal was scheduled to play there Friday night.

Among the first physicians to respond to the wounded Friday was Patrick Pelloux, an emergency room doctor and former Charlie Hebdo writer who was among the first to enter the offices Jan. 7 to find his friends and colleagues dead.

The country has seen several smaller-scale attacks or attempts since, including an incident on a high-speed train in August in which American travelers thwarted an attempted attack by a heavily armed man.

France’s military is bombing Islamic State targets in Syria and Iraq and fighting extremists in Africa, and extremist groups have frequently threatened France in the past.

French authorities are particularly concerned about the threat from hundreds of French Islamic radicals who have travelled to Syria and returned home with skills to stage violence.

Though it was unclear who was responsible for Friday night’s violence, the Islamic State is “clearly the name at the top of everyone’s list,” said Brian Michael Jenkins, a terrorism expert and senior adviser to the president of the Washington-based RAND Corporation.

Jenkins said the tactic used — “multiple attackers in coordinated attacks at multiple locations” — echoed recommendations published in the extremist group’s online magazine, Dabbiq, over the summer.

“The big question on everyone’s mind is, were these attackers, if they turn out to be connected to one of the groups in Syria, were they homegrown terrorists or were they returning fighters from having served” with the Islamic State group, Jenkins said. “That will be a huge question.”

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)

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