"Does (Israel) think it can enter Lebanon with the most modern aircraft and tanks to kill women and children, and destroy schools and hospitals, and then expect us to remain silent?" Erdogan said at a conference organised by the Union of Arab Banks.
"Does it think it can use the most modern weapons, phosphorus munitions and cluster bombs to kill children in Gaza and then expect us to remain silent? "We will not be silent and we will support justice by all means available to us."
Turkey was once Israel's closest military and diplomatic ally in the Middle East but ties began to deteriorate when Ankara criticised Israel's December 2008 to January 2009 offensive against Gaza.
Relations then nosedived on May 31, 2010 when Israeli naval commandos stormed a Turkish-registered protest ship, the Mavi Mara, part of a flotilla attempting to break the Israeli blockade of the Palestinian territory. Nine Turkish activists were killed in the operation.
Erdogan has said his country will not begin to restore relations with Israel until it apologizes for its "savage attack" on the vessel. Thursday was the final day of the Turkish premier's two-day visit to Lebanon.
Hundreds of Lebanese of Armenian descent have clashed with army troops during a protest over a visit to Beirut by the Turkish prime minister.
Recep Tayyip Erdogan is on a two day trip during which he met with officials and visited the north and south of the country.
He was inaugurating a hospital in the southern port city of Sidon Thursday as hundreds of protesters gathered in the capital's Martyrs' Square.
When demonstrators tore up a large poster of Erdogan and pelted troops with rocks, security responded by beating up a number of them.
There were no reports of major injuries.
Lebanon has 150,000 Armenians, or nearly 4 percent of its population, which harbors deep animosity toward Turks over the 1915 killing of up to 1.5 million Armenians.
AFP and AP contributed to the story
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