During its invasion of Russian and Persian territory, Ottoman paramilitaries massacred local Armenians; massacres turned into genocide following the catastrophic defeat in the Battle of Sarikamish (January 1915), which was blamed on Armenian treachery. In the minds of the Ottoman leaders, isolated indications of Armenian resistance were taken as evidence of a coordinated conspiracy that did not exist in reality. Armenian soldiers in the Ottoman Army were disarmed pursuant to a February order and later killed. On 24 April 1915, the Ottoman authorities rounded up, arrested, and deported hundreds of Armenian intellectuals and community leaders from Constantinople (now Istanbul).