At least 12 Palestinians were killed and hundreds of others injured Friday by Israeli security forces along the Israel-Gaza border, the Palestinian Health Ministry said.
The Israeli military said its troops used "riot dispersal means" to quell one of the largest Palestinian demonstrations and outbursts of violence along the border in recent years.
Violence erupted as thousands of Palestinians approached the border. The Israeli military said its troops responded to "main instigators" who were throwing stones and rolling burning tires.
The ministry said Israeli forces fired live bullets, rubber-coated steel pellets and tear gas, killing at least 12 Palestinians and injuring at least 550 others.
It was the deadliest day in Gaza, a self-governing Palestinian territory, since last fall.
Palestinians have constructed protest tent camps along the entire length of the Gaza Strip in five locations that are expected to remain in place for six weeks. Entire families — men, women, and children — were expected to participate in the tent camp demonstrations.
The weeks-long demonstrations, to end on May 15, are designed to commemorate the Nakba or "catastrophe" when hundreds of thousands of Palestinians had to flee their land or were expelled during the war in 1948 that led to the creation of Israel.
Israeli Defense Minister Avigdor Liberman warned the Gaza demonstrators in an Arabic post on Twitter: "The leadership of Hamas is playing with your lives. Anyone who comes close to the fence today puts himself at risk. I suggest to you to continue your lives and not participate in a provocation."
Israel has deployed more than 100 snipers along the Gaza Strip.
The demonstrations are expected to end at the same time Washington plans to open an embassy in Jerusalem, a move that has infuriated Palestinians who have claimed the eastern section of the city as the capital of their future state.
On Thursday, Danny Danon, Israel's ambassador to the U.N., said the demonstrations are an "organized planned provocation" and asserted "Israel's right to defend its sovereignty and protect its citizens."