Medics treated 431 people with various injuries, including 98 wounded by live fire and rubber bullets, the Gaza health ministry said.
Israeli soldiers thwarted an attempt by Gaza Arabs to breach the Gaza border fence and infiltrate Israel, the military said Sunday in a statement.
A military spokeswoman said that some of the protesters threw stones at the Israeli forces.
Gaza media initially reported the blast as a "work accident", implying the terrorists were killed while producing or handling explosives.
Video released by al-Jazeera showing Palestinians cutting through Gaza border fence on May 4, 2018.
A statement from the Palestinian Islamist group's armed wing on Saturday called the incident a "deplorable Zionist crime" perpetrated against its fighters by Israel.
Hamas says the protests are aimed at breaking a crippling border blockade that was imposed by Israel and Egypt after the Islamic militant group assumed control of Gaza in 2007.
The area is near the border with Israel, where more than 40 Palestinians have been killed by Israeli forces in protests that began on March 30, dubbed by organisers as "The Great March of Return".
The source also notes that the cause of the explosion could be an improvised explosive device.
Palestinians mark the date as their "nakba", or catastrophe, when hundreds of thousands of Palestinians fled or were displaced in the 1948 war over Israel's creation.
Since 1948, the Israeli regime has denied Palestinian refugees the right to return, despite United Nations resolutions and worldwide law that uphold people's right to return to their homelands. The IDF also believes that the number of dead and injured is being exaggerated by the Palestinian side.