Several nations have voiced outrage after Israeli troops fired near a delegation that included two Irish diplomats in the West Bank, with the Tánaiste calling the incident "a clear breach of law".
The Palestinian Authority accused Israeli troops of "deliberately" shooting at the delegation near the flashpoint city of Jenin.
The Israeli military, already under pressure over its tactics in the Gaza war, said it regretted the "inconvenience".
AFP footage from Jenin, a frequent target of Israeli military raids, showed the delegation, that included two Irish diplomats, and accompanying journalists running for cover as shots were heard.
The two Irish diplomats caught up in the incident were the head of mission in the Irish Representative Office in Palestine along with the deputy head of the mission.
A European diplomat said the envoys went to the area to see the destruction caused by Israeli military raids since the Gaza war erupted in October 2023.
The Israeli military said the diplomatic convoy strayed from the approved route and entered a restricted zone.
Israeli troops fired "warning shots" to steer the group away, it said, adding that no one was wounded and expressing regret for the "inconvenience caused".
UN Secretary General Antonio Guterres's spokesperson called the incident "unacceptable".
"Diplomats who are doing their work should never be shot at, attacked in any way, shape or form. Their safety, their viability, must be respected at all times," the spokesperson, Stéphane Dujarric, told reporters.
"These diplomats, including UN personnel, were fired at, warning shots or whatever ... which is unacceptable," he added.
Several countries that had representatives in the group voiced outrage and demanded an investigation.
European Union foreign policy chief Kaja Kallas urged Israel to hold those responsible "accountable".
Belgium, Canada, France, Germany, Italy, the Netherlands, Portugal, Spain and Uruguay summoned Israel's ambassadors or said they would raise the issue directly.
Tánaiste Simon Harris said the firing of shots by the Israeli military yesterday in vicinity of a delegation is the latest in a trend of intimidatory behaviour by the Israeli Defence Forces towards diplomats.
Speaking on RTÉ's Morning Ireland, the Minister for Foreign Affairs called the incident "a clear breach of law", adding that Israel has an obligation to protect diplomats.
The visit would have been very much part and parcel of their representative work and the Israeli Defense Forces would have been notified of that visit in advance, the minister said.
He added there must be accountability for the incident and this was conveyed to the Israeli Ambassador for Ireland last night.
Canadian Prime Minister Mark Carney called the incident "totally unacceptable" and pressed for an "immediate explanation".
Mr Carney added that Canada's Foreign Minister Anita Anand has summoned Israel's ambassador to Ottawa.
Watch: IDF fires warning shots during diplomatic delegation visit to Jenin
Egypt denounced the shooting as a breach of "all diplomatic norms", while Turkey demanded an immediate investigation.
Turkey's foreign ministry said: "This attack must be investigated without delay and the perpetrators must be held accountable."
Ahmad al-Deek, political adviser for the Palestinian foreign ministry who accompanied the delegation, condemned "this reckless act by the Israeli army".
"It has given the diplomatic delegation an impression of the life the Palestinian people are living," he said.
Palestinian news agency Wafa reported the delegation included diplomats from more than 20 countries including Britain, China, Egypt, France, Japan, Jordan, Turkey and Russia.
Japan's government confirmed that its diplomatic staff participated, adding that it "deeply regrets" the incident.
"The Japanese government has protested to the Israeli side and requested an explanation and the prevention of a recurrence," government spokesperson Yoshimasa Hayashi said in Tokyo.
The incident came as anger mounted over the humanitarian crisis in Gaza, where Palestinians are scrambling for basic supplies after weeks of near-total isolation.
A two-month Israeli aid blockade on Gaza has been partially eased this week.
The UN said yesterday that it had "dispatched" around 90 trucks carrying aid into Gaza.
The first aid distribution in Gaza since early March came as Israeli Prime Minister Benjamin Netanyahu said he was open to a "temporary ceasefire", but reaffirmed the military aimed to bring the entire territory under its control.
Three days after Israel announced it would allow in limited aid, the United Nations "collected around 90 truckloads of goods from the Kerem Shalom crossing and dispatched them into Gaza", Mr Dujarric said.
In Gaza, the Hamas government media office reported the arrival of 87 aid trucks, which it said were allocated to international and local organisations to meet "urgent humanitarian needs".
Mr Netanyahu said it was necessary to "avoid a humanitarian crisis in order to preserve our freedom of operational action" in Gaza.
Palestinians have been scrambling for basic supplies after weeks of near-total isolation, with Israel's blockade leading to critical food and medicine shortages.
'Unbearable'
Israel has meanwhile kept up its bombardment, with Gaza's health ministry reporting yesterday that the bodies of 82 people were taken to hospitals across the territory over the previous 24 hours.
Umm Talal al-Masri, 53, a displaced Palestinian in Gaza City, described the situation as "unbearable".
"No one is distributing anything to us. Everyone is waiting for aid, but we haven't received anything," she said.
Humanitarian groups have said that the amount of aid entering Gaza falls far short of what is required to ease the crisis.
A US-backed private group, the Gaza Humanitarian Foundation (GHF), that will use contractors, said that it will start moving aid into the territory in "coming days".
The United Nations and traditional agencies have said they will not cooperate with the foundation which some have accused of working with Israel.
The GHF has said it will distribute some 300 million meals in its first 90 days of operation
Israel stepped up its military offensive at the weekend, vowing to defeat Gaza's Hamas rulers, whose 7 October 2023 attack on Israel triggered the war.
Israel has faced massive pressure, including from its allies, to halt its intensified offensive and allow aid into Gaza.
European Union foreign ministers on Tuesday ordered a review of the EU cooperation accord with Israel.
Sweden said it would press the EU to impose sanctions on Israeli ministers, while Britain suspended free-trade negotiations with Israel and summoned the Israeli ambassador.
Pope Leo XIV described the situation in Gaza as "worrying and painful" and called for "the entry of sufficient humanitarian aid".
Hamas's 2023 attack resulted in the deaths of 1,218 people in Israel, mostly civilians, according to an AFP tally based on official figures.
Militants also took 251 hostages, 57 of whom remain in Gaza including 34 the military says are dead.
Gaza's health ministry said at least 3,509 people have been killed since Israel ended a ceasefire and resumed strikes on 18 March, taking the war's overall toll to 53,655, mostly civilians.
