FACTBOX: Background to Turkish Armenian massacres dispute

(Reuters) - Turkey warned on Thursday that relations with its NATO ally the United States would be harmed by a U.S. House committee's approval of a resolution calling the 1915 massacres of Armenians by Ottoman Turks genocide.

The House of Representatives Foreign Affairs committee approved the resolution on Wednesday and it now goes to the House floor, where Democratic leaders say there will be a vote by mid-November.

Here are some details about the issue:

* THE BACKGROUND:

-- In the late 19th century the Ottoman Empire's Armenian minority, numbering an estimated 2 million, was encouraged by exiled groups in the United States, Geneva and in the Georgian capital, Tbilisi, to assert its nationalism.

-- Repression by Ottoman irregulars, mainly Kurds, led to the massacre of some 30,000 Armenians in eastern Anatolia in 1894-1896. Several thousand more were killed in Constantinople in August 1896 after Armenian extremists seized the Ottoman Bank to draw attention to their cause.

-- The massacres were halted after the Great Powers threatened to intervene.

* WHAT HAPPENED IN 1915:

-- As the Ottomans fought Russian forces in eastern Anatolia during World War One, many Armenians formed partisan groups to assist the invading Russian armies.

-- On April 24, 1915, Turkey arrested and killed hundreds of the Armenian intelligentsia. In May of that year Ottoman commanders began the mass deportation of Armenians from eastern Turkey thinking they might assist Russian invaders.

-- Thousands were marched from the Anatolian borders toward Syria and Mesopotamia (now Iraq) and Armenians say some 1.5 million died either in massacres or from starvation or deprivation as they were marched through the desert.

* TURKEY'S VIEW:

-- Turkey has always denied there was a systematic campaign to annihilate Armenians, saying that thousands of Turks and Armenians died in ethnic violence as the Ottoman Empire started to collapse and fought a Russian invasion of its eastern provinces during World War One.

-- The modern Turkish republic was established in 1923 after the Ottoman empire collapsed.