The Gaza Health Ministry said at least 80 Palestinians were wounded by live fire and that six of them were in serious condition.
The Israeli military said about 13,000 protesters massed at several points along the fence, some burning tires and hurling rocks, grenades and firebombs. An Israeli officer suffered light wounds from pipe bomb shrapnel.
At night fall, two tank shells hit a watchtower that had been set up by Hamas, the Islamic militant group in control of Gaza. The tower was about half a mile from one of the protest camps near the fence, and protesters left in a hurry as they heard the thud of the shells.
The Israeli military said in statement that aircraft and a tank struck two Hamas positions in response to the explosives thrown at troops on the border.
Gazans have staged near weekly demonstrations near the fence since late March, in part to protest a border blockade enforced by Israel and Egypt since 2007 when Hamas seized the territory. Hamas has led and organized the protests, but turnout has also been driven by growing despair over blockade-linked hardship, including lengthy power cuts and soaring unemployment.
Israeli soldiers have killed at least 131 Palestinians during the weekly protests since March, including 27 minors, according to the Gaza Health Ministry. A Palestinian sniper also fatally shot an Israeli soldier.
Israel contends it's defending its border and accuses Hamas of using the protests as a screen for attempts to breach the border fence to attack civilians and soldiers. Human rights groups have accused Israeli troops of excessive and unlawful use of force against unarmed protester.
Hamas and Israel came close to serious conflict earlier this summer as violence soared along the border. The two sides have negotiated indirectly through Egyptian mediators to ease tensions in exchange for lifting some of the restrictions on the economically crippled Gaza Strip. But those efforts have stalled in recent weeks.
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