Tens of thousands marched in Istanbul Monday to protest "murderer" Israel's war on Gaza and the killing of Turkish soldiers by outlawed Kurdish militants in Iraq.

The rally, called by a foundation which counts Bilal Erdogan, the son of President Recep Tayyip Erdogan, among its members started after crowds performed morning prayers at Istanbul's iconic mosques, including Hagia Sophia and the Blue Mosque.

Protesters waving Turkish and Palestinian flags rallied to the Galata Bridge on the Bosphorus chanting: "Murderer Israel, get out of Palestine" and "Allahu Akbar" (God is the greatest).

Tens of thousands of people joined the rally "Mercy for our martyrs and a curse on Israel", the official Anadolu news agency reported.

Erdogan, a vocal supporter of the Palestinian cause, has lashed out repeatedly at Israel for the scale of death and destruction caused by its war.

He has accused Israel of "state terrorism" and said Israeli Prime Minister Benjamin Netanyahu was "no different" from Adolf Hitler.

Israel launched a punishing offensive in the Gaza Strip on October 7, one that has reduced vast areas of the Palestinian enclave to a ruined wasteland and killed at least 21,822 people, mostly women and children.

The Israeli army says 172 of its soldiers have been killed inside Gaza, with the war showing no signs of stopping.

The Turkish army said 12 soldiers were killed in late December in two separate attacks launched by the Kurdistan Workers' Party (PKK) in northern Iraq.

Turkey regularly conducts ground and air operations in northern Iraq against the positions of the PKK, listed as a terror group by Ankara and its Western allies.