Prime Minister Binyamin Netanyahu said the demonstrators were challenging “the very existence of Israel” and, in nationally broadcast remarks, pledged that the country was “determined to defend our borders and sovereignty.”
Palestinians commemorate Israel’s founding as al-Naqba, or the catastrophe, marking the displacement of hundreds of thousands in the war that followed Israel’s declaration of independence.
The coordinated protests on Sunday were organized using many of the social media tools that have propelled revolts in Arab countries in recent months, and the message they carried, of Palestinian demands for the right to return to their ancestral homes, struck a raw nerve among Israelis, who have been watching the popular uprisings with concern that they could strengthen groups hostile to Israel.
Some Israeli officials pointed a finger at Syria and its ally Iran, accusing them of instigating the protests to deflect attention from the deadly repression of the anti-government demonstrations in Syria.
The Israeli army’s chief spokesman, Brig. Gen. Yoav Mordechai, said Syrian and Lebanese troops had failed to hold back the demonstrators, who had arrived in busloads from Palestinian refugee camps.
The most serious incident was on the border between Syria and the occupied Golan Heights, where thousands of protesters gathered on the Syrian side and hundreds flooded into the Israeli-held territory after flattening the border fence. Scores entered the Druze village of Majdal Shams, gathering in the central square, where they raised Palestinian flags.
“We cannot put up with this anymore. We are demanding our right of return,” said Muhammad Umran, 35, from the Yarmouk refugee camp in Syria’s capital, Damascus, who spoke by telephone from Majdal Shams. “We are not afraid,” he said, adding that his family was originally from a village near the city of Safed.
Another protester, Muhammad Suleiman, also from the Yarmouk camp, said by telephone that the crowds had passed through minefields and planted Syrian and Palestinian flags on an Israeli army jeep vacated by troops during the rock-throwing melee. The empty jeep was visible in television broadcasts from the scene.
Israeli troops opened fire to drive back the protesters, killing two, according to Israeli officials and Syrian television, which said that more than 100 were injured. The Syrian Foreign Ministry described the Israeli actions as “criminal acts.”
Soldiers later rebuilt the fence, and by nightfall nearly all the protesters were returned to Syria, an Israeli army spokeswoman said.