Thousands mass at pro-Palestinian rally called by Erdogan: AFP

Thousands of people massed in Istanbul for a rally called by Turkish President Recep Tayyip Erdogan to show solidarity with the Palestinians and condemn Israel after its deadly shootings of Gaza protesters, an AFP correspondent said on Friday.

Large crowds thronged the massive Yenikapi meeting area on the shores of the sea of Marmara under the slogan "Curse the oppression, support Jerusalem", ahead of an address by Erdogan.

Demonstrators held Palestinian and Turkish flags and brandished slogans like "Jerusalem is our red line”.

The rally came hours ahead of an extraordinary summit meeting of the Organisation of Islamic Cooperation (OIC) also called by Erdogan to denounce Israel's actions and the moving of the US embassy for Israel from Tel Aviv to Jerusalem.

Some of the leaders and ministers set to attend the summit were present at the rally, including Palestinian prime minister Rami Hamdallah.

"We are calling on the world and say 'Israel, America and Zionism, you all dragged humanity into chaos'," said protestor Levent Ayaz. 

"With God's permission, Jerusalem belongs to us and is the capital of Islam as long as this ummah (Islamic community) exists," he added.

"There is no political view here, there is no right, there's no left," said fellow demonstrator Recep Kerven. 

"The only reason we are here is to support our (Palestinian) brothers. That's a message delivered to the entire world.”

Erdogan hosted 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".

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. 

Just hours after the demonstrations, the UN Human Rights Council voted to send a team of international war crimes investigators to probe the deadly shootings of Gaza protesters by Israeli forces.