The deadly outcome of today's protests in Gaza against the U.S. relocation of its embassy from Tel Aviv to Jerusalem caused widespread condemnations from around the world, with calls on Israel to use more restraint against Palestinians. In the evening the death count reached 55 with signs that it might still be rising.

The UN's top human rights official, Zeid Ra'ad al-Hussein, took to Twitter to decry the "shocking killing of dozens, injury of hundreds by Israeli live fire," adding that "the right to life must be respected".

United Nations Secretary-General Antonio Guterres said he was "deeply concerned with the incidents that took place in Gaza."

Meanwhile, Kuwait is calling for an emergency U.N. Security Council meeting to be summoned in the wake of the Gaza violence.

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EU foreign policy chief Federica Mogherini called on Israel to abide by the "principle of proportionality in the use of force" and to "respect the right to peaceful protest," saying security forces must use the "utmost restraint to avoid further loss of life." Speaking of demonstrators in Gaza, however, she said Hamas "must not exploit them for other means".

A spokesperson of British Prime Minister Theresa May also voiced "concern" over "violence and loss of life in Gaza," while France's foreign minister Jean-Yves Le Drian said "all actors" should "show responsibility to prevent a new escalation." "France again calls on the Israeli authorities to exercise discernment and restraint in the use of force that must be strictly proportionate," he added.

Open gallery view Pro-Islamist demonstrators march during a protest in support of Palestinians and against the U.S. moving its embassy to Jerusalem, in Istanbul, Turkey May 14, 2018 Credit: \ OSMAN ORSAL/ REUTERS

Germany's Foreign Ministry said it was "shocked and deeply concerned" by the death toll, adding that Israel's right to self-defense does not mean it doesn't have to abide by the principle of proportionality.

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"The right to peaceful protest must also apply in Gaza. At the same time, we have always made clear that this right must not be abused, taken as a pretext or exploited in order to escalate the situation, deploy violence or incite others to do so," the statement said.

Harshly worded condemnations of the Gaza violence also came from the Muslim world, with spokesman of Turkey’s President Recep Tayyip Erdogan Ibrahim Kalin speaking of "another dark spot, another crime added to Israel's wall of shame." "The so-called civilized world must be ashamed of its silence in the face of this systematic barbarism," he wrote in a tweet.

Turkey's Foreign Ministry said the embassy's move has encouraged Israeli forces to kill Palestinian protesters. "We curse the massacre carried out by Israeli security forces, encouraged by this step, on the Palestinians participating in peaceful demonstrations," the statement said.

Open gallery view Turkish Police officers outside the Israeli Ambassador's residence in Ankara during a demonstration against the move of the U.S. embassy from Tel Aviv to Jerusalem, Monday, May 14, 2018 Credit: Burhan Ozbilici/AP

Also Turkish Prime Minister Binali Yildirim condemned Israel harshly: "Unfortunately, the U.S. has arrogantly stood by the Israeli administration which kills civilians and has partnered in this crime against humanity," he said. Turkey has been very vocal in its criticism of Israel in the last few years despite the reopening of an Israeli embassy in Ankara in 2016 after 10 years.

Demonstrators carried a banner reading "Al Quds belongs to the Muslims," using the Arabic name for Jerusalem, in a march in solidarity to Palestinians in Istanbul. In the capital Ankara Turkish police surrounded the house of Israeli ambassdor Eitan Na'eh while in the front a group of protestors chanted slogans flying Palestinian flags. Turkish President Erdogan called for a bigger gathering "against oppression" on Friday in Istanbul.

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In Egypt, a statement from the Foreign Ministry condemned "the use of force against peaceful marches" but did not mention the opening of the U.S. embassy, which is the main motive behind today's protests.

Saudi Arabia condemned the "targeting of unarmed Palestinians" in a statement from its Foreign Ministry while Qatar decried "the brutal massacre and systematic killing committed by the Israeli occupation forces."

Finally, Israel's archenemies Hezbollah and Iran slammed Israel for the Gaza violence, with Syria's Foreign Ministry also protesting the "brutal massacre."

Associated Press, Reuters and DPA contributed to this report