Violent clashes erupted along the Gaza Strip's border ahead of the controversial opening of the US embassy in Jerusalem on Monday, leaving 37 Palestinians dead from Israeli fire and hundreds wounded in the conflict's bloodiest day in years.
The clashes took place as a White House delegation and Israeli officials gathered for the embassy inauguration ceremony in Jerusalem. It was the bloodiest day in the Israeli-Palestinian conflict since a 2014 Gaza war.
The dead included a 14-year-old, according to the Gazan health ministry, which also provided the overall death toll.
Tens of thousands had gathered near the border in protest while smaller numbers of stone-throwing Palestinians approached the fence and sought to break through, with Israeli snipers positioned on the other side.
Crowds built throughout the day in the Palestinian enclave less than 100 kilometres (60 miles) away from Jerusalem and sealed off from Israel by a blockade.
Israel's military said "over 35,000 Palestinians are currently taking part in violent riots in 12 locations along the Gaza Strip security fence."
"The rioters are hurling firebombs and explosive devices towards the security fence and (Israeli) forces, and are burning tyres, throwing rocks and launching flaming objects in order to ignite fires in Israeli territory and harm (Israeli) troops."
It said soldiers were responding with "riot dispersal means and fire."
The Palestinian Authority government based in the occupied West Bank accused Israel of committing a "terrible massacre."
The inauguration that follows US President Donald Trump's deeply controversial December 6 recognition of the disputed city as Israel's capital also comes at a time of heightened regional tensions.
In a tweet on Monday, Trump hailed the embassy opening as "a great day for Israel".
It follows Trump's announcement last week that the United States is withdrawing from the Iran nuclear deal and Israeli strikes two days later on dozens of Iranian targets in Syria.
Those strikes came after rocket fire toward Israeli forces in the occupied Golan Heights that Israel blamed on Iran.
Monday's inauguration ceremony at 4:00pm (1300 GMT) will include around 800 guests — though not Trump himself — at what until now had been a US consulate building in Jerusalem.
US Deputy Secretary of State John Sullivan will lead the Washington delegation that includes Trump's daughter Ivanka and her husband Jared Kushner, both White House aides, as well as Treasury Secretary Steven Mnuchin.
'Capital for all time'
Israeli Prime Minister Benjamin Netanyahu, who has repeatedly called Trump's decision "historic", welcomed them at a reception on Sunday.
"Jerusalem has been the capital of the Jewish people for the past 3,000 years," he said.
"It's been the capital of our state for the past 70 years. It will remain our capital for all time."
Sullivan called the embassy "a long overdue recognition of reality."
Saeb Erekat, Palestine Liberation Organisation secretary-general, called it a "hostile act against international law".
Police and the Israeli military deployed massively.
Around 1,000 police officers have been positioned around the embassy for the inauguration.
Israel's army said it was almost doubling the number of troops surrounding Gaza and in the occupied West Bank.
It also dropped leaflets warning Gazans to stay away from the fence, including one with a photo of the Champs-Elysees boulevard in Paris and the caption: "Gaza 2025? The choice is in your hands."
Israeli Defence Minister Avigdor Lieberman said in a message to Gazans "we will protect our civilians with all our means and not enable the fence to be crossed."
Israelis began celebrating on Sunday, as tens of thousands of marched in Jerusalem, some holding American flags, to mark Jerusalem Day.
The annual event is an Israeli celebration of the "reunification" of the city following the 1967 Six-Day War.
Israel occupied the West Bank and east Jerusalem in 1967 and later annexed east Jerusalem in a move never recognised by the international community.
Beyond the disputed nature of Jerusalem, the date of the embassy move is also key.
May 14 marks the 70th anniversary of the founding of Israel.
The following day, Palestinians mark the "Nakba", or catastrophe, commemorating the more than 700,000 Palestinians who fled or were expelled from their homes in the 1948 war surrounding Israel's creation.
Palestinian protests are planned on both days.
'Off the table'
There had already been weeks of protests and clashes along the Gaza border, with 91 Palestinians killed by Israeli fire there since March 30.
No Israelis have been wounded and the military has faced criticism over the use of live fire.
Israel says it only opens fire when necessary to stop infiltrations, attacks and damage to the border fence, while accusing Hamas, the Islamist movement that runs the blockaded Gaza Strip, of seeking to use the protests as cover to carry out violence.
Jerusalem's status is perhaps the thorniest issue in the Israeli-Palestinian conflict.
Israel considers the entire city its capital, while the Palestinians see east Jerusalem as the capital of their future state.
In the decades since 1967, international consensus has been that the city's status must be negotiated between the two sides, but Trump broke with that to global outrage.
He has argued that it helps make peace possible by taking Jerusalem "off the table", but many have pointed out he has not announced any concessions in return from Israel.
Trump's initial decision led to a series of protests in various Middle Eastern and Muslim countries.