ISRAELI TROOPS CLASHED with Arab protesters Sunday along three hostile borders, including the frontier with Syria, leaving at least 12 people dead and dozens wounded in an unprecedented wave of demonstrations marking a Palestinian day of mourning for their defeat at Israel’s hands in 1948.

In the most serious incident, the Israeli military said thousands of protesters approached Syria’s border with the Israeli-controlled Golan Heights and hundreds burst through the fence.

Earlier reports had put the death toll at five.

Soldiers opened fire to stop them, the military said. Dozens were wounded and four were reported killed.

It was a rare incursion from the usually tightly controlled Syrian side, and Israeli officials accused Damascus of fomenting the violence in an attempt to divert attention from the deadly crackdown on protests within its borders against the rule of President Bashar Assad.

“The Syrian regime is intentionally attempting to divert international attention away from the brutal crackdown of their own citizens to incite against Israel,” said Lieutenant Colonel Avital Leibovich, an Israeli military spokeswoman.

Israeli media reported that the incident was over by early evening, but the military did not immediately confirm that.

Prime Minister Benjamin Netanyahu said he had ordered the military to act with “maximum restraint.”

Sunday’s unrest — which came after activists used Facebook and other websites to mobilize Palestinians and their supporters in neighboring countries to march on the border with Israel— marked the first time the protest tactics that have swept the Arab world in recent months have been directed at Israel.

Deadly clashes also took place along Israel’s nearby northern border with Lebanon, as well as in the Gaza Strip, near Israel’s southern border.

The Israeli military said 13 soldiers were lightly wounded in the Lebanon and Syria clashes.

In addition, hundreds of Palestinian threw stones at Israeli police and burned tires at a checkpoint outside Jerusalem before they were dispersed.

The unrest came as the Palestinians marked the “nakba,” or “catastrophe,” the term they use to describe their defeat and displacement in the war at the time of Israel’s founding in 1948. Hundreds of thousands of Palestinians were uprooted, and the dispute over the fate of the refugees and their descendants, now numbering several million, remains a key issue in the Mideast conflict.

In Egypt, the army set up at least 15 checkpoints — guarded by tanks and armored vehicles — on the road between the Egyptian town of El-Arish and the Gaza border city of Rafah, turning back all who were not residents of the area.

Israeli TV channels broadcast scenes, taken from Arab stations, of what appeared to be thousands of people gathering along the Syrian border with the Golan. In a statement, the military said “thousands of Syrian civilians” breached the border.

Israeli officials confirmed two of those who crossed the Syrian border were dead on the Israeli side, and two were reported dead in Syrian territory.

The protesters were believed to be Palestinians who live in refugee camps in Syria. Israel’s Channel 2 TV interviewed one of those who crossed, who identified himself as a resident of the Yarmouk refugee camp in Syria. “I am Palestinian from Nazareth,” a town in northern Israel, the man told the station.

By late afternoon, Israeli military officials said about 100 people had been caught and were being sent back to Syria. It was not known how many remained on the loose.

“The residents are in shock, they had no idea this was going to happen,” Dolan Abu Salah, mayor of Majdal Shams, told Channel 10 TV. He said the town’s residents, members of the Druse Arab sect, were neutral and did not want to get involved.

About 25 miles to the west, Israeli troops clashed with a large crowd of Lebanese demonstrators who approached the border. The military said it opened fire when protesters tried to damage the border fence. Lebanese security officials reported six dead.

It was one of the most serious incidents along the volatile border since Israel fought Lebanese Hezbollah guerrillas during a monthlong war five years ago.

The shooting erupted at the tense border village of Maroun el-Rass, which saw some of the fiercest fighting in 2006.

Thousands of Palestinian refugees had traveled to the village in buses adorned with posters that said: “We are returning.” Many came from the 12 crowded refugee camps in Lebanon where some 400,000 Palestinian refugees live.

“Israel may be 63 years old today but its days are numbered,” said Abbas Jomaa, 50, who was carrying his 4-year-old son on his shoulders and holding a Palestinian flag. “Sooner or later we will return.”

Hundreds of Lebanese soldiers, UN peacekeepers and riot police deployed heavily in the area, taking up positions along the electric border fence and patrolling the area in military vehicles. Young Hezbollah supporters wearing yellow hats and carrying walkie-talkies organized the entry to the village and handed out Palestinian flags.

Palestinian medics also said one person was killed and 65 others were wounded when demonstrators in the Gaza Strip tried to approach a heavily fortified border crossing into Israel.

A second Palestinian was killed in a separate incident. Israel’s military said he was trying to plant a bomb along the fence.

Inside Israel, police were on high alert for disturbances among the country’s large Arab minority. In a reflection of the jitters, a deadly traffic incident involving an Arab truck driver in Tel Aviv set off fears that an attack had been carried out.

The truck plowed through a crowded street, crashing into a bus, several cars and pedestrians, killing one and injuring 16 others. Police said the 22-year-old driver claimed it was an accident, but said they were still investigating.

“Based on the devastation and debris, we’re still examining if it was carried out deliberately,” said police spokesman Micky Rosenfeld.

- AP