Palestinian protesters react from tear gas canisters fired by Israeli troops during clashes near the border with Israel, in the east of Gaza City.

Israeli soldiers and a settler shot dead two Palestinians who tried to stab Jews in separate incidents in annexed east Jerusalem and the occupied West Bank on Saturday, the army and police said.

In the first attack at just before 0600 GMT, a Palestinian tried to stab an Israeli settler in the center of the West Bank city of Hebron near a Jewish enclave where 500 settlers live under army protection surrounded by nearly 200,000 Palestinians.

The settler responded by opening fire on his assailant, the army said, adding that the Palestinian had tried but failed to wound the Jewish man.

Palestinian sources identified the alleged assailant as 18-year-old Fadel al-Kawatsmi and confirmed his death.

Minutes later in Israeli-annexed east Jerusalem, a second Palestinian was shot and killed by Israeli forces when he tried to stab a soldier at a checkpoint, police said.

Police spokeswoman Louba Samri said the Palestinian, who was not immediately identified, was killed on the spot after he tried to stab the soldier in the Israeli settlement neighborhood of Armon Hanetsiv, also known as East Talpiot.

Israeli security forces have deployed massively in Jerusalem after two weeks of Palestinian attacks in the city and across Israel.

The violence has sparked fears that a third Palestinian intifada, or uprising against Israeli occupation, could break out.

In the Palestinian uprisings of 1987-1993 and 2000-2005, thousands were killed and many more wounded in near daily violence.

The latest incidents come a day after Palestinians called for a “Friday of revolution” against Israel.

They also follow a Thursday night arson attack on Joseph’s Tomb, a shrine in the West Bank city of Nablus which many Jews believe to be the final resting place of the biblical patriarch Joseph.

The shrine, where Muslims believe an Islamic cleric, Sheikh Yussef (Joseph) Dawiqat was buried two centuries ago, is under Palestinian control.

The violence began on October 1, when a suspected cell of the Islamist movement Hamas murdered a Jewish settler couple in the West Bank in front of their children.

Those killings followed repeated clashes at east Jerusalem’s Al-Aqsa mosque compound in September between Israeli forces and Palestinian youths.

U.S. President Barack Obama expressed concern Friday about the outbreak of violence centered in Jerusalem, and called on Israeli and Palestinian leaders to tamp down inflammatory rhetoric.

Obama’s statement comes amid mounting clashes in Israel and the Palestinian territories that have raised fears of a full-scale surprising.

“We are very concerned about the outbreak of violence,” Obama said at a news conference with visiting South Korean President Park Geun-Hye.

“We condemn in the strongest possible terms violence directed against innocent people, and believe that Israel has a right to maintain basic law and order and protect its citizens from knife attacks, and violence on the streets,” he added.

“We also believe that it’s important for both Prime Minister (Benjamin) Netanyahu and Israeli elected officials, and President Abbas and other people in positions of power, to try to tamp down rhetoric that may feed violence or anger or misunderstanding,” he said.

At 37 Palestinians have died and hundreds more been wounded in clashes, while at least seven Israelis have been killed and dozens wounded in the violence.

“Over time, the only way that Israel is going to be truly secure, and the only way the Palestinians will be able to meet the aspirations of their people, is if they are two states living side by side in peace and security,” Obama said.

But right now, he said, “everybody needs to focus on making sure that innocent people aren’t being killed.”

Meanwhile U.S. Secretary of State John Kerry, in Milan as part of a European tour, called Netanyahu on Friday to discuss “how best to end the recent wave of violence, and to offer U.S. support for efforts to restore calm as soon as possible,” a State Department official said.

On Thursday Kerry called Palestinian president Mahmoud Abbas and “reiterated the importance of avoiding further violence and preventing inflammatory rhetoric, accusations and actions that will increase tensions,” the official said, speaking on condition of anonymity.

Kerry also said he “hoped to visit the region at the appropriate moment.”

Netanyahu and Kerry are planning to meet in Berlin next week, according to U.S. and Israeli officials, although the exact details have yet to be confirmed.