Paris —Three teams of extremists carried out the coordinated gun-and-suicide bombing attacks across Paris that left 129 people dead and 352 injured, a French prosecutor said Saturday.

Paris prosecutor Francois Molins said 99 of the injured were in critical condition after the "act of barbarism." He said the attackers in the Bataclan concert hall, where 89 people died, mentioned Syria and Iraq during their deadly rampage.

French President Francois Hollande has vowed that France will wage "merciless" war on the Islamic State group, after the jihadists claimed responsibility for the attacks Friday night.

Belgium's federal prosecutor's office says authorities have so far made three arrests linked to the deadly attacks in Paris.

Spokesman Jean-Pascal Thoreau says the arrests at the Belgian border came after a car with Belgian license plates was seen close to the Bataclan theater in Paris on Friday night, one of the places where victims were killed.

He said it was a rental vehicle and police organized several raids in the St. Jans Molenbeek neighborhood in Brussels on Saturday.

Paris prosecutor Francois Molins says one of the hostage takers involved in a deadly siege at the Bataclan concert hall in Paris was born in France. He also says a French national was among three people linked to the Paris attacks arrested Saturday morning at the Belgian border.

Molins said a different suicide attacker identified by a Syrian passport found near his body at the national stadium was not known to French intelligence services.

He said all seven suicide attackers wore identical explosives vests.

Bryan Clement, a 19-year-old student in Nancy, France, was one of dozens of people posting have-you-seen-me? photos of friends and family missing since the Paris attacks.

Clement said the posts were similar to the posters, flyers and photos plastered around New York in the wake of Sept. 11, 2001 but "now it's digital." He says "now everyone can help with the search."

At least 127 people died Friday night in shootings at Paris cafes, suicide bombings near France's stadium and a massacre inside a concert hall. The Islamic State group has claimed responsibility.

Parisians desperate to get in touch with family and friends missing since Friday's coordinated attacks in Paris are taking to social media under the hashtag #rechercheparis — "Paris Search" in English — posting heartfelt messages and photos.

Scores of people that attended the six sites targeted in the attacks in which at least 127 people died are still unaccounted for.

One post reads: "Waleed is missing. We last contacted him at the match, Please share & contact me if u have any info. #rechercheParis".

Another: "I've been looking for my cousin since last night... He's 25 and 1m75. He's called Younes. #rechercheParis "

The photos and messages are garnering hundreds of retweets — from users eager to help in the search for survivors.

Leading French movie theater chains are shutting their Paris cinemas after attacks on a concert hall, stadium and cafes that left at least 127 people dead.

The UGC and Gaumont Pathe chains said in tweets that they would close their Paris movie theaters for a day Saturday after the bloodshed Friday night in the French capital.

Several entertainment and cultural sites in Paris have also closed their doors Saturday, including Disneyland Paris, the Eiffel Tower and the Louvre Museum.

In addition to rallying the nation after the shocking terror attack on Paris, French President Francois Hollande has been on the phone talking about fighting terror with other world leaders.

Those include the Turkish president Recep Tayyip Erdogan, who is hosting the G-20 summit on Sunday. Erdogan assured the French president that the Paris attacks that killed 127 people Friday night will be a "top priority" on the G-20 agenda.

Hollande also spoke on the phone with German Chancellor Angela Merkel, Italian Prime Minister Matteo Renzi, King of Morocco Mohammed VI, Greek Prime Minister Alexis Tsipras, Belgian Prime Minister Charles Michel, European Council President Donald Tusk, U.K. Prime Minister David Cameron and Egyptian President Abdel-Fattah el-Sissi.

Two French police officials say that authorities have identified one of the suicide bombers who targeted Paris in deadly attacks as a young Frenchman flagged in the past for links with an Islamic extremist activity.

The officials said the man was among attackers who blew himself up after a rampage and hostage-taking in a Paris concert hall.

Earlier, police officials said at least one of the suicide bombers who targeted another site, France's national stadium, was found to have a Syrian passport.

None of the attackers has been publicly identified.

The officials spoke on condition of anonymity because they were not authorized to be publicly named.

A State Department spokesman confirms that Americans are among the injured in the Paris terror attacks.

The department's deputy spokesman, Mark Toner, says Saturday that "the U.S. Embassy in Paris is working around the clock to assist American citizens affected by this tragedy." He would not comment if any were killed.

The Islamic State group has claimed responsibility for the attacks, considered the deadliest on France since World War II. At least 127 people died Friday night in shootings at cafes, suicide bombings near France's stadium and a massacre inside a concert hall.

French President Francois Holland has declared three days of mourning and raised the nation's security to the highest level.

Ahsan Naeem, a Paris resident for years, says he and his friends — one of whom was hit by "bullet shrapnel" inside the Bataclan club ---- were still in shock after the deadly attacks that rocked Paris.

Naeem, a 39-year-old filmmaker, says "these places are the places we visit every week ... streets we walk every day. I've seen dozens of gigs at the Bataclan. Eaten at the Petit Cambodge. Sat outside Le Carillon on so many nights."

Eric Berliet, a 20-year-old student, was consumed with worry over a family friend, also 20, who was shot three times and is now "at death's door" at Saint-Antoine hospital in Paris. He says "there's sadness and anger like never before" among his friends.

He says they often go to Bataclan and nearby venues and he has a ticket at one for next week. He says "I have no idea whether I'll go now."

The governor of Bavaria says the arrest of a man in Germany last week may be linked to the Paris attacks.

A spokesman for Bavarian state police spokesman confirmed that firearms, explosives and hand grenades were found when undercover police stopped a man near the German-Austrian border on Nov. 5.

Ludwig Waldinger declined to confirm reports by public broadcaster Bayrischer Rundfunk that the man appeared to be en route to Paris when he was arrested.

Bavarian governor Horst Seehofer told reporters Saturday there were "reasonable grounds" to assume that there may be a link to the Paris attacks.

British police say they've arrested a man and called in explosive specialists at Gatwick Airport amid heightened concerns following the terror attacks in Paris.

The North Terminal at Gatwick has been evacuated as police dealt with the incident Saturday.

Police say they were called at around 9.30 a.m. (GMT) after suspicious actions by the man, who had discarded an item.

Detective Superintendent Nick May says the matter is under investigation and it is too early to say what the item may be. But he says that "given the events in Paris on Friday evening, there is heightened awareness around any such incident and it is best that we treat the matter in all seriousness."

Gatwick is Britain's second busiest airport.

France's interior minister has authorized local authorities to impose curfews if needed after the deadliest attacks in the country since World War II.

Bernard Cazeneuve said in a televised address Saturday that authorities are also banning all public demonstrations until Thursday.

Cazeneuve laid out increased security measures across the country, including thousands more troops and police and special protection for certain public buildings.