Israel’s borders erupted in deadly clashes on Sunday as thousands of Palestinians — marching from Syria, Lebanon, Gaza and the West Bank — confronted Israeli troops to mark the anniversary of Israel’s creation. More than a dozen people were reported killed and scores injured.

With an unprecedented wave of coordinated protests, the popular uprisings that have swept the region touched Israel directly for the first time. Like those other protests, plans for this one spread over social media, including Facebook, but there were also signs of official support in Lebanon and Syria, where analysts said leaders were using the Palestinian cause to deflect attention from internal problems.

At the Lebanese border, Israeli troops shot at hundreds of Palestinians trying to force their way across. The Lebanese military said 10 protesters were killed and more than 100 were wounded. Israel said it was investigating the casualties.

In the Golan Heights, about 100 Palestinians living in Syria breached a border fence and crowded into the village of Majdal Shams, waving Palestinian flags. Troops fired on the crowd, killing four people. The border unrest could represent a new phase in the uprising against President Bashar al-Assad of Syria.

In the West Bank, about 1,000 protesters carrying Palestinian flags and throwing stones and occasional firecrackers and gasoline bombs fought with Israeli riot troops near the military checkpoint between Ramallah and Israel. Scores were injured, local medical officials said.

In Gaza, when marchers crossed a security zone near the border, Israeli troops fired into the crowd, wounding dozens.

In Jordan and Egypt, government security forces thwarted protesters headed to the border.

Every year in mid-May, many Palestinians observe what they call “the nakba,” or catastrophe, the anniversary of Israel’s declaration of independence in 1948 and the war in which hundreds of thousands of Palestinians lost their homes through expulsion and flight. But this was the first year that Palestinian refugees and their supporters in Syria, Lebanon, Jordan and Egypt, inspired by the recent protests around the Arab world, tried to breach Israel’s military border from all sides.

“The Palestinians are not less rebellious than other Arab peoples,” said Ali Baraka, a Hamas representative in Lebanon.

At day’s end, as a tense calm returned to the country’s borders, Prime Minister Benjamin Netanyahu of Israel said the protests had been aimed at destroying Israel, not creating a Palestinian state alongside it.

“The leaders of these violent demonstrations, their struggle is not over the 1967 borders but over the very existence of Israel, which they describe as a catastrophe that must be resolved,” he said. “It is important that we look with open eyes at the reality and be aware of whom we are dealing with and what we are dealing with.”

Mahmoud Abbas, the president of the Palestinian Authority, saluted the protesters in a televised speech, referring to the dead as martyrs. “The blood of the nakba fatalities was not spilled in vain,” he said. “They died for the Palestinian people’s rights and freedom.”

Officials and analysts have argued that with peace talks broken down and plans to request the United Nations to declare Palestinian statehood in September, violence could return to define this conflict, relatively quiet for the past two years.

“This is war,” said Amjad Abu Taha, a 16-year-old from Bethlehem who joined the protesters in Ramallah, a rock in one hand and a cigarette in the other. “We’re defending our country.”

Nearby, hundreds of Israeli troops roamed the area, using stun guns and tear gas.

In Gaza, the Hamas police stopped buses carrying protesters near the main crossing into Israel, but dozens of demonstrators continued on foot, arriving at a point closer to the Israeli border than they had reached in years and drawing Israeli fire.

Later, in a separate episode, an 18-year-old Gazan near another part of the border fence was shot and killed by Israeli troops when, the Israeli military says, he was trying to plant an explosive.

At the Syrian border, an Israeli military spokesman said, troops fired only at infiltrators trying to damage the security barrier and equipment there. Some 13 Israeli soldiers were lightly wounded from thrown rocks.

The chief Israeli military spokesman, Brig. Gen. Yoav Mordechai, said on Israel Radio that he saw Iran’s fingerprints in the coordinated confrontations, although he offered no evidence. Syria has a close alliance with Iran, as does Hezbollah, which controls southern Lebanon, and Hamas, which rules in Gaza.

Yoni Ben-Menachem, Israel Radio’s chief Arab affairs analyst, said it seemed likely that President Assad of Syria was seeking to divert attention from his crackdown on the popular uprisings there by allowing confrontations in the Golan Heights for the first time in decades.

“This way Syria makes its contribution to the Nakba Day cause, and Assad wins points by deflecting the media’s attention from what is happening inside Syria,” he added.

There were also signs of grass-roots support for the protests.

Palestinian activists have called on the Internet for a mass uprising against Israel to begin on May 15. A Facebook page calling for a third Palestinian intifada, or uprising, had gathered more than 300,000 members before it was taken down in March after complaints that comments posted to it advocated violence.

In Egypt, political organizers worked for weeks to rally Egyptians around the idea of a third intifada.

In Lebanon, activists had urged Palestinians to protest at the border town of Maroun al-Ras. Posters went up on Lebanese highways reading, “People want to return to Palestine,” playing on the slogan made famous in Egypt and Tunisia, “People want the fall of the regime.”

Israel declared its independence on May 14, 1948. Israelis celebrate the anniversary according to the Hebrew calendar, which this year was last Tuesday.

The day’s troubles began when an Israeli Arab truck driver rammed his truck into cars, a bus and pedestrians in Tel Aviv, killing one man and injuring more than a dozen in what the police described as a terrorist attack.

Later, hundreds of Lebanese joined by Palestinians from more than nine refugee camps in Lebanon headed toward Maroun al-Ras, scene of some of the worst fighting in the 2006 war between Israel and Hezbollah.

Though the Lebanese Army tried to block them from arriving at the border fence, some reached it. They placed Palestinian flags at the fence, and after Israeli troops fired on them, some threw rocks at the soldiers, witnesses said.

In Egypt, too, the government tried to prevent an international confrontation, sending troops to the border in anticipation of a planned march there from Cairo.

About 250 people were stopped at El Arish, in the northern Sinai, where they were demonstrating for Egypt to open the border with Gaza, expel the Israeli ambassador and stop selling natural gas to Israel. About 30 activists made it around military checkpoints to stage a small demonstration at the border crossing.

Several thousand Egyptians protested in front of the Israeli Embassy in Cairo, waving Palestinian flags, clapping and chanting “Down with Israel.” After midnight some protesters tried to storm the embassy and were repelled by Egyptian Army guards, witnesses reported.

In Jordan, 800 Palestinians were bused to the border, but security officials and local residents prevented them from going further. During the clashes that resulted, 14 demonstrators and three police officers were hurt, one critically, according to Jordan’s public security office.

The fact that protesters made it to the border in Lebanon and Syria raised questions about whether those governments had endorsed the actions.

Protesters in Lebanon said they received permission from the army to enter the border area near Maroun al-Ras, classified as a militarily sensitive region.

Hezbollah was believed to have helped coordinate the march. A field hospital affiliated with the group, the Martyr Salah Ghandour Hospital, which operates in Bint Jbeil, a large town in southern Lebanon, was at the scene.

In Syria, dozens of checkpoints safeguard the border area, which has been relatively peaceful since a truce in 1974. The arrival of hundreds, if not thousands, would require government permission, or at least official acquiescence.

A Syrian dissident, citing accounts from Damascus residents, said pro-government Palestinian groups began busing people to the border on Saturday night.