Israeli soldiers have shot and killed at least 52 Palestinians and left another 1,200 injured during mass protests along the Gaza border, health officials said.
It was the deadliest day in the region since a devastating 2014 cross-border war, and cast a shadow over the inauguration of the new US embassy in Jerusalem.
In a show of anger fuelled by the embassy move, Palestinian protesters set tyres ablaze and hurled firebombs and stones toward Israeli troops across the border. Later, Israeli forces opened fire from tanks, sending protesters fleeing for cover.
The military said its troops came under fire in some areas, and claimed protesters had been attempting to break through the border fence. It said troops shot and killed three Palestinians who were trying to plant a bomb.
The UN human rights chief said on Twitter that “Israeli live fire in #Gaza must stop now”, and demanded respect for human life.
Zeid Ra’ad al-Hussein decried the “shocking killing of dozens” and the injury of hundreds by Israeli forces in the Palestinian areas. Mr Zeid, a Jordanian prince who is leaving his post in August after a single term, said the international community needs to ensure justice for the victims.
He added on the UN human rights office’s Twitter feed that perpetrators of “outrageous human rights violations” must be held to account.
US president Donald Trump said in a video message played at the new US embassy inauguration – which took place just 45 miles from the bloodshed on the Gaza border – that he remains committed to “facilitating a lasting peace agreement” between Israelis and Palestinians.
“A great day for Israel!” Mr Trump tweeted earlier.
However, Monday’s steadily climbing death toll and wall-to-wall condemnation of the embassy move by the Arab world raised new doubts about Mr Trump’s ambitions to broker what he once said would be the Middle East “deal of the century”.
By late afternoon, at least 52 Palestinians, including five minors, were killed, the Gaza health ministry said. A total of 1,204 were wounded by Israeli gunfire.
The ministry says this total includes 116 people who were in serious or critical condition.
At the embassy ceremony in Jerusalem, Mr Trump’s son-in-law and chief Middle East adviser Jared Kushner placed the blame on the Gaza protesters.
He said: “As we have seen from the protests of the last month and even today those provoking violence are part of the problem and not part of the solution.”
Mr Kushner and Mr Trump’s daughter Ivanka led a high-powered American delegation that also included the treasury secretary and four Republican senators.
The new embassy will temporarily operate from an existing US consulate, until a decision has been made on a permanent location.
In Gaza, the Hamas-led protest was meant to be the biggest yet in a campaign against a decade-old blockade of the territory. The Israeli military estimated a turnout of about 40,000, saying this fell short of what Hamas had hoped for.
The march was also directed at the inauguration of the embassy.
Mr Trump added in his video address that the new embassy was opening “many, many years ahead of schedule”, adding that the US had “failed to acknowledge the obvious” for many years.
He said that he remains committed to “facilitating a lasting peace agreement”, and that he was “extending a hand of friendship to Israel, the Palestinians and to all of their neighbours”.
Moving the embassy from Tel Aviv to Jerusalem – a key Trump campaign promise – infuriated the Palestinians, who seek east Jerusalem as a future capital.
The clash is the biggest showdown in years between Israel’s military and Gaza’s Hamas rulers along the volatile border. The sides have largely observed a ceasefire since the 2014 cross-border war – their third in a decade.
The protests mark the culmination of a campaign, led by Hamas and fuelled by despair among Gaza’s two million people, to break the blockade of the territory imposed byIsrael and Egypt after Hamas seized control of Gaza in 2007.
Since weekly border marches began in late March, 94 Palestinian protesters have been killed and more than 2,500 wounded by Israeli army fire. Hamas said four members, including three security men, were among the dead on Monday.
The timing of Monday’s events was deeply symbolic, both to Israel and the Palestinians.
The US said it chose the date to coincide with the 70th anniversary of Israel’s establishment. But it also marks the anniversary of what Palestinians call their “nakba”, or catastrophe, a reference to the uprooting of hundreds of thousands who fled or were expelled from present-day Israel during the 1948 war surrounding Israel’s creation.
Mr Trump’s decision to move the American embassy from Tel Aviv to Jerusalem was welcomed by Israel and condemned by the Palestinians.
Israel captured east Jerusalem in the 1967 Middle East war and annexed it in a move not recognised by the international community. The Palestinians seek the city’s eastern half as the capital of a future state.
Palestinian president Mahmoud Abbas has cut ties with the Trump administration and declared it unfit to mediate peace talks.
Palestinians seek east Jerusalem as a capital and view the Trump administration’s change in policy as a blatant show of pro-Israel bias. Israeli prime minister Benjamin Netanyahu has repeatedly praised Mr Trump’s decision to upend decades of US policy by recognising Jerusalem as Israel’s capital.
European foreign ministers have said the embassy move is unwise and likely to exacerbate tensions in the region. Their comments come after the Czech Republic, Hungary and Romania blocked the full 28-nation European Union from publishing a statement about the US move.