POPE FRANCIS's use of the word "genocide" to characterise the killing of an estimated 1.5 million Armenians in Turkey 100 years ago has led to a diplomatic row between Ankara and the Vatican, and has reawakened the controversy surrounding those events.

Speaking before a mass at St Peter's, in Rome, the Pope described the slaughter of the Armenians as "the first genocide of the 20th century. . . The remaining two were perpetrated by Nazism and Stalinism. And, more recently, there have been other mass killings, like those in Cambodia, Rwanda, Burundi, and Bosnia."

It was his duty, he said, to honour the memories of those who were killed, because "concealing or denying evil is like allowing a wound to keep bleeding without bandaging it."

In a separate message to the worldwide Armenian community, the Pope spoke of "that horrific massacre which was a true martyrdom of your people, in which many innocent people died as confessors and martyrs for the name of Christ.

"Even today, there is not an Armenian family untouched by the loss of loved ones due to that tragedy: it truly was Metz Yeghern - the 'Great Evil' - as it is known by Armenians. On this anniversary, I feel a great closeness to your people, and I wish to unite myself spiritually to the prayers which rise up from your hearts, your families, and your communities."

Turkey responded by summoning the Vatican's ambassador in Ankara to protest, saying that the government felt "great disappointment and sadness" at his remarks. The Turkish Foreign Ministry criticised Pope Francis, saying that he had ignored "the atrocities suffered by the Turkish and Muslim peoples who lost their lives".

The Turkish President, Recep Tayyip Erdoğan, said in a statement to a business group on Tuesday: "We will not allow historical incidents to be taken out of their genuine context and be used as  tool to campaign against our country.

"I condemn the Pope and would like to warn him not to make similar mistakes again."

Away from the political arguments, however, some ordinary Turkish people have dismissed the exchange, and are calling for history to be left to rest.

The controversy over the 1915 killings is one of the many examples in the Middle East of animosity between communities because of differing interpretations of history: the differences between the Israelis and Palestinians are perhaps the most obvious example.

Although Turkey admits that many Armenians died, it says that the number was about half a million. The Turkish version is that the deaths resulted from a conflict during the First World War, when Armenians allegedly sought to challenge Ottoman rule.

Turkey has always insisted that Muslims, too, were killed, and that Armenians were not deliberately slaughtered because they were Christians. Most historians disagree, and believe that the Armenians were victims of ethnic cleansing on a mass scale.

There seems little prospect of Turkish attitudes' changing, particularly under the current Islamist-leaning regime. Turkey is also less likely than before to sympathise with the current plight of Christians in the Middle East, who face threats from jihadist Islamists in several states.

In his address, Pope Francis referred to the challenges facing the region's Christians. Today, he said, "we are experiencing a sort of genocide created by a general and collective indifference, by the complicit silence of Cain."

'Centenary of the Armenian massacres' - Letters