Turkish President Recep Tayyip Erdoğan announced that the country will observe a national day of mourning on Friday for Ismail Haniyeh, the head of Hamas's political bureau, who was killed on Wednesday in Tehran, coinciding with his burial in Qatar. Erdoğan wrote on the X platform: "A national day of mourning has been declared for tomorrow (Friday, August 2) to show our support for the Palestinian cause and our solidarity with our Palestinian brothers and sisters." He condemned the "treacherous assassination" of his "brother" Ismail Haniyeh, blaming "Zionist barbarism" for this assassination. The Turkish president had hosted Haniyeh in Istanbul last April. On Wednesday evening, thousands marched in Istanbul to protest the killing of the Hamas leader, which the Palestinian movement attributed to Israel. Haniyeh's coffin arrived in the Qatari capital on Thursday. After Friday prayers, Haniyeh is set to be buried in Qatar, where he had been residing with other members of Hamas's political bureau, following prayers at the Imam Muhammad ibn Abd al-Wahhab Mosque, the largest mosque in Doha.