Turkish President Recep Tayyip Erdogan on Friday hosts Muslim leaders for an Istanbul summit to condemn Israel over the killing of Gaza protesters, seeking to bridge divisions with the Islamic world and issue a strong message.
Erdogan has reacted with unbridled fury to the killing by Israeli forces on Monday of 60 Palestinians on the Gaza border, accusing Israel of "genocide" and being run as an "apartheid state".
He has also called a mass demonstration in Istanbul expected to rally hundreds of thousands from 1300 GMT ahead of the summit's start at 1600 GMT.
Erdogan already staged an extraordinary meeting of the Organisation of Islamic Cooperation (OIC) in December last year to denounce US President Donald Trump's decision to recognise Jerusalem as the capital of Israel.
"We must give the toughest response ... to the crime against humanity committed by Israel," Foreign Minister Mevlut Cavusoglu told a meeting of OIC foreign ministers ahead of the summit.
A draft communique prepared for the summit calls for "international protection for the Palestinian people" and condemns Israel's "criminal" actions against "unarmed civilians".
The text also accuses the US administration of "encouraging the crimes of Israel" and condemns the move of the US embassy from Tel Aviv to the contested holy city of Jerusalem, according to participants in the summit.
- 'OIC disunity upsetting' -
However, as in 2017, disputes between the OIC's key players -- notably between Sunni kingpin Saudi Arabia and Shiite Iran -- may prevent the adoption of any measures going beyond harsh rhetoric.
Riyadh -- which appears to have softened its stance on Israel as the influence of powerful Crown Prince Mohammed bin Salman has grown -- and its allies fear alienating the United States with tough measures against Tel Aviv.
Saudi's chief foreign policy preoccupation, shared with Israel, is ensuring US backing to contain Iran which both Riyadh and the Jewish state see as the main threat to regional peace.
Egypt and Saudi Arabia distrust Turkey's support for Islamist movements like the Muslim Brotherhood and Hamas, complicating any effort to take concrete measures against Israel.
Cavusoglu also said some OIC member states' failure to show enough support for the Palestinian cause "upsets us".
Speaking in Geneva, UN human rights chief Zeid Ra'ad Al Hussein slammed Israel's reaction to the Gaza protests as "wholly disproportionate", backing calls for an international investigation.
Israel accused Gaza's Islamist rulers Hamas of using the protests to carry out attacks and exploiting the Palestinian population.
- 'Curse the oppression' -
After declaring his intention to hold the event only on Monday, Erdogan has managed to build up an impressive guest list at short notice.
Jordanian King Abdullah II will be present although the Palestinians will be represented by prime minister Rami Hamdallah and not president Mahmud Abbas who this week had surgery on his ear.
From the Gulf, Kuwait's Emir Sheikh Sabah al-Ahmad Al-Sabah is expected as is Emir Sheikh Tamim bin Hamad Al-Thani of Qatar, Turkey's main regional ally.
Egyptian Foreign Minister Sameh Shoukry and Saudi counterpart Adel al-Jubeir will be at the Istanbul summit but not their heads of state.
Iranian President Hassan Rouhani will attend, state media said, and overcoming the enmity between Tehran and Riyadh will be crucial for the Turkish hosts.
As in the November 2017 meeting, a controversial guest will be Sudanese President Omar al-Bashir, who is wanted on charges of genocide and war crimes by the International Criminal Court (ICC).
Erdogan has long craved a role as a Muslim leader within the entire Islamic world, rarely holding back with tirades against Israel even though Ankara has diplomatic relations with the Jewish state.
Tensions with Israel and hosting such a meeting also does Erdogan no harm with his core supporters as Turkey heads to presidential and parliamentary polls on June 24.
In a diplomatic crisis threatening a 2016 deal that allowed the resumption of full ties, Turkey has ordered the Israeli ambassador to leave for an unspecified period of time over the killings.
The rally expected just before the summit is set to take place at the Yenikapi meeting area favoured by Erdogan for election rallies under the slogan "curse the oppression".