JERUSALEM — Clashes between hundreds of Palestinian protesters and Israeli troops erupted across the West Bank on Thursday while demonstrators in Gaza burned posters of President Donald Trump and Israeli Prime Minister Benjamin Netanyahu, as well as Israeli and U.S. flags.

The leader of the Hamas militant group, which runs Gaza, called for a new armed uprising in a widespread show of anger over Trump’s move to recognize Jerusalem as Israel’s capital.

In the West Bank, crowds of protesters set tires on fire and hurled stones at anti-riot troops. In the biblical town of Bethlehem, troops fired water cannons and tear gas to disperse a crowd, in clashes that could cloud the upcoming Christmas celebrations in the town of Jesus’ birth. In Ramallah, the seat of the Palestinian government, protesters set tires on fire, sending a thick plume of black smoke over the city.

Trump’s dramatic break on Wednesday with decades of U.S. policy on Jerusalem counters long-standing international assurances to the Palestinians that the fate of the city will be determined in negotiations. The Palestinians seek Israeli-annexed east Jerusalem, captured by Israel in 1967, as a future capital.

Palestinians shuttered their schools and shops on Thursday to begin three “days of rage” over Trump’s decision. Rallies were underway in other West Bank cities, and a demonstration was being held outside the Damascus Gate of Jerusalem’s Old City.

There were no serious casualties reported in Thursday’s clashes. But Friday, the Muslim holy day, could provide an important test when Palestinians gather for weekly mass prayers.

In the Gaza Strip, Hamas’ leader Ismail Haniyeh called on Palestinians to launch a new intifada, or uprising, against Israel on Friday.

“The American decision is an aggression on our people and a war on our sanctuaries,” Haniyeh said in a speech, urging supporters “to be ready for any orders.”

“We want the uprising to last and continue to let Trump and the occupation regret this decision,” he said.

The Israeli military said it would deploy several battalions to the West Bank ahead of Friday, while other troops have been put on alert to address “possible developments.”

The conflicting claims to Jerusalem, and especially its Old City, where sensitive Jewish, Muslim and Christian holy sites are located, lie at the core of the Israeli-Palestinian conflict. While Trump’s decision had no impact on the city’s daily life, it carried deep symbolic meaning, and was seen as siding with Israel and an attempt to impose a solution on the Palestinians.

Israel, which claims all of Jerusalem as its undivided capital, has welcomed Trump’s decision. Netanyahu said Trump “bound himself forever” to the history of Jerusalem with the move and claimed other states are considering following suit.

“We are already in contact with other states that will make a similar recognition,” he said at the Foreign Ministry on Thursday.

Anger at the U.S. has rippled across the Arab world.

Saudi Arabia’s royal court, led by King Salman and his powerful son, condemned the Trump administration’s decision in a rare public rebuke by the U.S. ally. The regional powerhouse, which could help the White House push through a Middle East settlement, said Thursday the kingdom had already warned against this step and “continues to express its deep regret at the U.S. administration’s decision,” describing it “unjustified and irresponsible.”

Trump’s claim Wednesday that he still wants to pursue what he has called the “ultimate” Mideast deal was met by mounting skepticism. Turkish President Recep Tayyip Erdogan on Thursday accused Trump of throwing the Mideast into a “ring of fire” and said his motives were difficult to fathom. “It’s not possible to understand what you are trying to get out of it,” Erdogan said, referring to Trump in a speech to a group of workers at Ankara’s airport.

U.S. Embassies across much of the Middle East and parts of Africa warned American citizens of possible protests following Trump’s move.

The Government of Canada updated its travel advisory to Israel, the West Bank and the Gaza Strip on Dec. 5 ahead of Trump’s announcement, and will uphold its validity to take into account ‘Day of Rage’ protests from Dec. 6-8. The advisory warns Canadians to “exercise a high degree of caution in Jerusalem due to protests and clashes between protestors and local authorities in East Jerusalem and parts of the Old City, and politically motivated attacks and violence throughout the city.” There is also an advisory for Bethlehem, Jericho and Ramallah, as “security situation can change rapidly”.