Incredible Photos From The "We Are Charlie" Unity March In Paris — PHOTOS

In the single largest demonstration in French history, a reported 3.7 million people have taken part in "We Are Charlie" unity marches across France in response to the deadly attacks last week that began at the Charlie Hebdo office and ended in 17 deaths over the course of three terrifying days. With estimates of up to 1.6 million people taking part of the march in Paris, some suggested that the show of solidarity was larger still than the celebration following the 1944 liberation of the city from Nazi Germany. Over 40 world leaders also took part of the demonstration, including British Prime Minister David Cameron, German Chancellor Angela Merkel, Israeli Prime Minister Benjamin Netanyahu, Palestinian President Mahmoud Abbas, Malian President Ibrahim Boubacar Keita, EU President Donald Tusk, and Jordan's King Abdullah II, exemplifying the international spirit of solidarity and camaraderie that has emerged as a result of the tragedy.

In response to the incredible turnout, French President Francois Hollande noted, "Today, Paris is the capital of the world. Our entire country will rise up toward something better." The march began shortly after 3 pm local time, with crowds wearing expressions of devastation, but not submission. Some chanted "liberte" ("freedom") and "Charlie," referencing the satirical magazine, while others waved French flags and held cartoons and signs that read, "I am Charlie." Fanny Appelbaum, a 75-year-old Holocaust survivor who told Reuters that she lost two sisters and a brother at Auschwitz, said, "We're not going to let a little gang of hoodlums run our lives. Today, we are all one."

The city has been on high alert for any further attacks in the aftermath of the latest tragedy, and Interior Minister Bernard Cazeneuv told NBC News that around 2,000 police and 1,350 soldiers were on guard as reinforcements for the march and at "sensitive sites" throughout Paris.

But despite the heightened security presence, one of the key purposes of the unity march is to stare fear in the face, many participants say. As Prime Minister Manuel Valls proclaimed, the demonstration "must show the power, the dignity of the French people who will be shouting out of love of freedom and tolerance."

Valls continued, "Journalists were killed because they defended freedom. Policemen were killed because they were protecting you. Jews were killed because they were Jewish.The indignation must be absolute and total — not for three days only, but permanently." And with nearly 2 million marching in Paris alone, and millions more across the country and the world, it seems that the indignation is here to stay.

Ashley Lenglet, who participated in the march, admitted that she was very afraid, but was motivated to take part in the demonstration because of her fear. Speaking to NBC, she said, "I'm scared for what going to happen in France, for the future and for the future of my children. But we'll fight and we are here to show the people who want to hurt that we are still here and we are in solidarity."

"On this day," US Attorney General Eric Holder said, "We are all French citizens."

Images: Twitter