By late afternoon, crowds had swelled, and black smoke from burning tires billowed over the demonstrations. At least 726 protesters were injured, a spokesman for Gaza's health ministry said, including more than 150 who were wounded by gunshots.
The protests Friday marked the fourth week of mass rallies for what organizers have called the “Great March of Return.” It was initially conceived as an effort to highlight the right of Palestinian refugees to return to land they left behind when Israel was created in 1948.
The demonstrations also underscore the plight of Palestinians living in Gaza, where a blockade has stunted the economy, and jobs and basic services are scarce.
Since the border protests began last month, 34 Palestinians have been killed and more than 4,000 injured, according to Palestinians. The United Nations has slammed Israel for “excessive use of force.”
Israel, in turn, said the protests are violent and provide cover for militant attacks. Israeli aircraft dropped fliers over the border areas Friday, urging protesters to stay away from the border fence.
“You are participating in violent riots,” the leaflets said. “Stay away from the terror instigators and violent riot orchestrators.”
In a statement Friday, Israeli Defense Forces said that 3,000 Palestinians participated in riots in five locations along the border.
Demonstrators, the army said, were “attempting to approach security infrastructure, burning tires adjacent to it and attempting to fly kites with burning items attached.”
Two Palestinian men were fatally shot in a border area in northern Gaza on Friday, the health ministry said.
On Thursday, the militant group Islamic Jihad released a video showing a gunman watching Israeli army officials through the scope of a rifle.
“You are killing our people in cold blood,” the video said. “And think that you are protected.”
All Palestinian factions in Gaza have supported the protests, including Hamas, the militant group that rules the 140-square-mile territory.
Israel has accused Hamas, which the United States has designated a terrorist organization, of using civilian protesters as shields to “terrorize Israel.”
Israel and Egypt have imposed travel and trade restrictions on the territory since Hamas took power in 2007. Hamas and Israel have fought three wars in Gaza in the past 10 years.
But while Hamas maintains its military wing, analysts say they have thrown their weight behind the demonstrations to pressure Israel without sparking another conflict. The media attention garnered by the protests prompted the group to change tactics.
At the demonstrations near Gaza City on Friday, Hamas officials toured a protest camp about 700 yards from the border. Its supporters were bused in from mosques in the area, and muscular men with closely-cropped beards patrolled the camp and checked participants' identification.
A large prayer site was set up, and a troupe performed an Arab and Palestinian folk dance called “dabke.”
“They realized after the first [protest] that they would achieve more with peaceful action, because they would lose a military confrontation” with Israel, Mukhaimar Abu Saada, a political analyst and professor at Gaza's al-Azhar University, said of Hamas.
“If Hamas decided not to participate, the number of protesters would be really low,” he said. “But the fear is that this will turn from a peaceful protest into a violent one. Throwing molotov cocktails is not peaceful — it's violent.”
The atmosphere near Gaza City was festive Friday, even as protesters clashed with Israeli troops at the fence. Vendors with carts and megaphones sold everything from nuts to ice cream to grilled liver sandwiches. Palestinians took selfies with posters of Palestinians held in Israeli jails.
Closer to the border, protesters were more hardened. At a small staging area in a dusty lot, masked youths launched kites with rags and plastic bottles attached, which they set alight with lighter fluid. Two kites were emblazoned with the Nazi symbol, which they flew over the border.
Elsewhere, they rolled massive tires that they would eventually set on fire. Volleys of tear gas sent crowds of Palestinians running, while others observed the chaos.
“To Jerusalem we go, with a million martyrs!” a group of demonstrators chanted.
“Watch out for the [tear] gas!” one protester yelled.
A Hamas-linked analyst, Naji Zaza, said that while Hamas is participating, the protests are the result of a grass-roots movement.
“All Palestinians in Gaza are suffering from the siege,” he said of Israel and Egypt's blockade. “These are ordinary people” at the protests.
But Hamas, he said, is “part of the community. And lifting the siege is a legitimate demand.”
Ruth Eglash contributed from Jerusalem.