Thousands of Armenian Christians rallied in different countries around the world including in Armenia, and in the United States to commemorate the 101st anniversary of Armenian genocide at the hands of Ottoman Empire in 1915 during World War I, which killed 1.5 million people.

On April 24, protestors marched with torchlights towards a hilltop memorial complex in capital city Yerevan. One of the marches was led by Hollywood star and human rights activist George Clooney, who is a steadfast advocate of the massacre's recognition as genocide.

Tens of thousands also gathered at the Turkish Consulate in Los Angeles, wearing purple shirts, and waving flags, according to LA Times.

"We want to show the youth what April 24 is about," US Rep. Adam Schiff (D-Burbank) said at the rally. "Obviously, we want justice. If we don't do this, it will be forgotten."

Refugees and supporters also assembled at City Park in Idaho to lay flowers in the memory of people slain in the massacre.

"It affects everybody when we have a sort of tragedy like this so it's important that we come together and make remembrance of such events," said Father Michael Habib of St. Ignatius of Antioch Church.

"Forget culture, forget religion. As people we need to support one another. Especially in times like this," he added.

The Archdiocese of Boston commemorated the event for the first time, which was attended by over 800 people.

"It is so important that we do not allow the events of the genocide to slip into oblivion," said Cardinal Sean P. O'Malley. "The one and a half million lives are not forgotten. . . . One of the fruits of their martyrdom is the accumulation of love that unites us."

The Vatican also recognized the first genocide of 20th century by holding a special mass, presided over by Pope Francis. The pope gave a message saying that everyone is obliged to not forget the "senseless slaughter," during the First World War.

"Concealing or denying evil is like allowing a wound to keep bleeding without bandaging it," the pope said.

Many stores in Los Angeles put up signs in English and Armenian informing closure of shops in remembrance of the genocide.

In 2015, Hollywood Boulevard and Western Avenue intersection was designated as Armenian Genocide Memorial Square, while in March, Glendale Unified became the first school district in United States to set apart April 24 as a day of remembrance of the genocide.

Up to 1.5 million Armenian Christians were murdered in Eastern Turkey through systematic killings and starvations between 1915 and 1923.

Similar protests were held in Jerusalem, Beirut, Iran, Canada, and Australia.