People observe a moment of silence November 16, 2015 at the Trocadero in front of the Eiffel Tower to pay tribute to the victims of the November 13 attacks in Paris.

A woman walks under flags flying at half staff at the Washington Monument on the National Mall in Washington, November 17, 2015.

President Barack Obama issued a proclamation ordering flags to fly at half staff as a mark of respect for victims of the Paris attacks.

A man waves a French flag as several hundred people gather to observe a moment of silence in Lyon, France, November 16, 2015, to pay tribute to the victims of the series of deadly attacks in Paris on November 13.

(From L) French Minister for Higher Education and Research Thierry Mandon, French Education Minister Najat Vallaud-Belkacem, French President Francois Hollande and French Prime Minister Manuel Valls observe a minute of silence at the Sorbonne University in Paris to pay tribute to victims of Friday's Paris attacks, France, November 16, 2015.

People observe a moment of silence in tribute to victims of the attacks in Paris in front of French embassy, near the Brandenburg Gate in Berlin, November 16, 2015.

People light candles during a vigil in Kathmandu on November 15, 2015, following the deadly attacks in Paris.

Flowers and candles are placed near the scene of a shooting the day after a series of deadly attacks in Paris, November 14, 2015. The sign reads "I am Paris."

People take part in a vigil to pay tribute to the victims of the November 13 Paris attacks, at Trafalgar Square in London, November 14, 2015.

Mourners gather in front of the Le Carillon restaurant on November 14, 2015 in Paris.

A general view shows the Tuileries Garden after it was closed in Paris, France, November 14, 2015, following the terrorist attacks.

A woman is comforted by others outside Le Carillon cafe and Le Petit Cambodge restaurant in Paris, Saturday Nov. 14, 2015, a day after more than 120 people were killed in a series of attacks in Paris.

A woman with a French flag painted on her face cries during a vigil for victims of the Paris terror attacks at Martin Place on November 14, 2015 in Sydney, Australia.

A woman reacts as she looks at the flowers and messages left at a rail cordon close to the Bataclan concert hall in the 11th arrondissement of Paris on November 14, 2015, the day after a series of attack on the city resulted in the deaths of more than 127 people and injured around 100 people.

Some 80 people were gunned down at the Bataclan late November 13, during a concert by the U.S. band Eagles of Death Metal.

Flowers and candles are placed outside Le Carillon bar on November 14, 2015, the day after deadly terrorist attacks in Paris.

French President Francois Hollande declared the attacks an "act of war." ISIS claimed responsibility for the attacks on the French capital.

French military patrol near the Eiffel Tower the day after a series of deadly attacks in Paris, November 14, 2015.

Bullet holes and marks are seen on the windows of the Cafe Bonne Biere restaurant on November 14, 2015 in Paris.

Mourners leave candles outside Le Carillon bar in the 10th arrondissement of Paris on November 14, 2015, following a series of attacks in and around the city.

Le Petit Cambodge, adjacent to Le Carillon, was the scene of another attack, which killed at least 12 people. The assailants struck at least six different venues, ranging from the Stade de France soccer stadium to a pizzeria.

Candles burn during a vigil outside the French embassy on November 14, 2015 in Seoul, South Korea.

People gather in Hong Kong, Saturday, November 14, 2015, to mourn the victims the Paris attacks.

People gather during a vigil in Aotea Square to remember victims of the Paris attacks on November 14, 2015 in Auckland, New Zealand.

Gun bullet impacts are seen on the windows of Le Carillon bar on November 14, 2015, the day after deadly terror attacks in Paris.

People observe a minute of silence for the victims killed in in the November 13, 2015 Paris terror attacks at the Sant Jaume square in Barcelona, Spain, Saturday, November 14 after more than 120 people were killed.

People finish arranging candles into the word "Paris" next to flowers and messages left at the gate of the French Embassy in Berlin on November 14, 2015, following the terror attacks in Paris on November 13.

Hundreds of people came throughout the day to lay flowers, candles and messages of condolence to mourn the victims of the attacks.

A pair of abandoned shoes seen in the street near the Bataclan concert hall the morning after a series of deadly attacks in Paris, November 14, 2015.

Dead bodies are evacuated near the Bataclan concert hall in the 11th arrondissement of Paris on November 14, 2015.

Concert goers were taken hostage during the attacks. The hostage situation ended with a police assault which left at least three attackers dead. Most of the victims of the multiple attacks were killed at the Bataclan concert hall.

A woman is evacuated from the Bataclan theater after a hostage situation and shootings in Paris, November 13, 2015.

Gunmen and bombers attacked busy restaurants, bars and a concert hall at locations around Paris on Friday evening, killing dozens of people in what a shaken French President described as an unprecedented terrorist attack.

Victims lay on the pavement outside a Paris restaurant, Le Carillon, in the same general neighborhood as the Charlie Hebdo offices in the 10th arrondissement on Friday, November 13, 2015.

A shaken French President described the violence as an unprecedented terrorist attack.

A French policeman assists a blood-covered victim near the Bataclan concert hall following attacks in Paris, November 14, 2015.

In addition to the deaths at the concert hall, a police official said 11 people were killed in a Paris restaurant in the 10th arrondissement and other officials said at least three people died when bombs went off outside the Stade de France.

People hug on the street near the Bataclan concert hall following deadly attacks in Paris, November 14, 2015.

French President Francois Hollande declared a state of emergency and announced the closing of France's borders.

Victims of a shooting attack lay on the pavement outside La Belle Equipe restaurant in Paris, November 13, 2015.

A member of the French fire brigade aids an injured individual near the Bataclan concert hall following fatal shootings in Paris, November 13, 2015.

Rescuers evacuate people following an attack in the 10th arrondissement of Paris on November 13, 2015.

A general view of the scene that shows rescue services personnel working near a covered bodies outside a restaurant following a shooting incident in Paris, November 13, 2015.

An injured man holds his head as people gather near the Bataclan concert hall following fatal attacks in Paris, November 13, 2015.

A policeman stands behind a cordon blocking the street near the site of an attack at the Petit Cambodge restaurant in Paris on November 13, 2015.

Investigating police officers work outside the Stade de France after an international friendly France-Germany soccer match, in Saint Denis, outside Paris, November 13, 2015.

French fire brigade members aid an injured woman near the Bataclan concert hall following fatal attacks in Paris, November 13, 2015.

Spectators gather on the pitch of the Stade de France following the friendly football match between France and Germany in Saint-Denis, north of Paris, on November 13, 2015, after a series of attacks occurred across Paris.

French President Francois Holland was at the match, but was evacuated.

People leave the Stade de France after the international friendly France-Germany soccer match, Friday, November 13, 2015 in Saint Denis, outside Paris.

General view of the scene with rescue service personnel working near covered bodies outside a restaurant following shooting incidents in Paris, November 13, 2015.

People run after hearing what is believed to be explosions or gun shots near Place de la Republique square in Paris on November 13, 2015.