Thousands turned out for a pro-Palestinian rally in Istanbul on Sunday, after sustained Israeli bombardment in the Gaza Strip and warnings about a ground attack there.

"They've been chasing people out of their homes for years. Now they're not killing people one by one day by day, they're killing them en masse," one of the marchers, Bayram Atabey, a shopkeeper in his thirties, told AFP.

"This is what Israel is doing and we are protesting against it," he added at the rally organised by a radical Islamist group allied to President Recep Tayyip Erdogan's Islamo-conservative AKP party.

Two other large-scale demonstrations took place on Friday and Saturday on Istanbul's historic peninsula to denounce Israel's response to the Palestinian Islamist movement Hamas's bloody attack on the Jewish state on September 7, the bloodiest ever committed on its territory.

One of Erdogan's sons, and a son-in-law, took part in Saturday's march.

During his two decades in power, Erdogan has repeatedly taken a stand in favour of the Palestinians, notably in a virulent indictment of former Israeli president Shimon Peres at the Davos forum in 2009.

Last year, however, he ended more than a decade of diplomatic rift with Israel.

In September he met Israeli Prime Minister Benjamin Netanyahu for the first time, on the sidelines of the United Nations General Assembly in New York.

This week the Turkish president nevertheless forcefully denounced "the indiscriminate massacre of innocent people in Gaza", asserting that Israel "does not behave like a state".