ISTANBUL (AP) — New Zealand's deputy prime minister is attending an emergency session of an umbrella organization of Muslim nations in Turkey after a gunman killed 50 people in two mosques in the South Pacific nation.

Winston Peters was in Istanbul on Friday for the 57-member Organization of Islamic Cooperation's executive committee meeting.

Australian Brenton Harrison Tarrant was arrested and charged with murder. Tarrant livestreamed the attack and released a manifesto describing his white supremacist views and how he planned the shootings.

Turkish President Recep Tayyip Erdogan, who will also speak at the summit, has sparked outrage abroad by screening at campaign rallies excerpts of the Tarrant's video to denounce Islamophobia. New Zealand has been trying to prevent the use of the video and Peters is expected to take up the issue.