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 US 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 US 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.

Hamas, a group that seeks Israel’s destruction, killed hundreds of Israelis in suicide bombings and other attacks in the early 2000s. But the group’s capabilities are more limited now. Gaza, Hamas’ stronghold, is closed by an Israeli blockade, while in the West Bank, many of its members have been arrested. Nonetheless, it possesses a large arsenal of rockets capable of striking much of Israel.

Spontaneous protests sparked in Gaza overnight, with angry youths burning tires, American and Israeli flags and Trump posters.

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 US 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 US 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 US administration’s decision,” describing it “unjustified and irresponsible.”

Trump’s move puts the Sunni nation in a bind. The kingdom, particularly its powerful crown prince, Mohammad Bin Salman, enjoys close relations with Trump and his son-in-law Jared Kushner, who leads Trump’s efforts to restart Mideast peace talks.

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

Palestinian President Mahmoud Abbas has suggested that with Trump’s move, the United States disqualified itself as mediator between Israelis and Palestinians, a role it has played exclusively in more than two decades of stop-and-go negotiations aimed at setting up a Palestinian state alongside Israel.

The talks, stalled in recent years, have failed to bring the Palestinians closer to the state the seek in the West Bank, Gaza Strip and east Jerusalem, lands Israel captured in the 1967 Mideast war. In parallel, Israel has steadily expanded Jewish settlements on war-won lands, even as it said it wants to negotiate a deal.

Trump’s claim Wednesday that he still wants to pursue what he has called the “ultimate” Mideast deal was met by mounting skepticism.

“With its decision, the US has isolated itself and Israel, and has pushed the area into a dangerous situation and stopped the peace process,” said Nabil Abu Rdeneh, a senior Abbas aid. “Without a doubt, this decision will not help at all in solving the problems in the area, but rather strengthen the extremists.”

Abbas has not said what steps he would take, if any. Later Thursday, he was to meet with his closest Arab ally, Jordan’s King Abdullah II, to coordinate positions.

Jordan plays a central role in the mounting controversy and, alongside other US allies in the region, has slammed Trump’s decision on Jerusalem.

The king is seen as one of Washington’s most dependable partners in the battle against Islamic extremism in the region.

At the same time, the legitimacy of his Hashemite dynasty is closely linked to its special role in Jerusalem, as religious guardian of a key Muslim shrine in east Jerusalem. Jordan, which has a large population with Palestinian roots, cannot afford to be seen as soft on Muslim claims to the holy city.

The consultations between the monarch and Abbas will kick off a series of meetings in the Arab and Muslim world on how to respond to Trump.

The Arab League, a group representing most states in the Middle East and North Africa, will meet Saturday. Next week, Turkey will host a gathering of the Organization of Islamic Cooperation, which has 57 Arab and Muslim member states.

The region has been bracing for fallout from Trump’s seismic policy shift.

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.