Today the 100th anniversary of the massacre of Armenians under the Ottoman Empire is being commemorated. Pope Francis recently referred to it as "the first genocide of the 20th century," and over 20 countries around the world agreed, though Turkey found issue with the statement.

Ceremonies are being held in Armenia to mark the centenary of the start of mass killings of Armenians by Ottoman Turks. Most estimates range between 600 thousand and 1,5 million Armenians were deported or assassinated from 1915-1923. The Ottoman authorities themselves reported 800,000 deaths between 1915 and 1918.

The victims were burned, drowned, tortured, raped, and poisoned. Many died from disease or starvation, including those who were been forcibly removed to Syria and sent to the desert.

The Young Turks wanted to nationalize the Empire when they came to power in 1908. In 1914, during World War I, they feared that the Armenians (who were Christians) would side with the Ottomans' enemy, Russia (also a Christian state).

The mass killings of Armenians began on April 24, 1915. On that very day 250 Armenian intellectuals and community leaders were arrested by the Young Turks. This day is knows as Red Sunday.

More than 20 countries, including Belgium, Canada, Austria, and Russia, consider the killings to be genocide. The United States is not in that list because it fears damaging relations with Turkey as an important ally. US President Barack Obama issued a statement for the anniversary that avoided using the term genocide, referring to the event as, "one of the worst atrocities of the 20th Century".

In Turkey genocide is still a very controversial word today. The #Government acknowledges that atrocities took place, although it denies the frightening figures. "It is out of the question," Recep Tayyip Erdogan, Turkey's president, said "for there to be a stain, a shadow called genocide on Turkey." After Pope Francis and Austria officially acknowledged the genocide, Turkey recalled its ambassadors from both the Vatican City and Vienna.

Today, on April 24, Turkey is hosting ceremonies to mark the 100th anniversary of the start of the Battle of Gallipoli. One of Turkey's oldest newspapers, Cumhuriyet, published a headline in Armenian - "Never Again".

During Mass in the Armenian Catholic rite, held at St. Peter's Basilica, Pope Francis said that, "concealing or denying evil is like allowing a wound to keep bleeding without bandaging it."