The UK has summoned Israel's ambassador in London to hear its "unequivocal condemnation" of the killing of three British and four other staff of a food charity in a Gaza missile strike.
The summons, which the Foreign Commonwealth and Development Office said the Israeli ambassador attended, came as Prime Minister Rishi Sunak called on Israel for answers about the "tragic incident".
Mr Sunak added that it must "take immediate steps to protect aid workers and facilitate vital humanitarian operations in Gaza".
Meanwhile, junior UK foreign minister Andrew Mitchell said after the summons that he had requested "a quick and transparent investigation, shared with the international community, and full accountability".
"I reiterated the need for Israel to put in place an effective deconfliction mechanism immediately and urgently to scale up humanitarian access," Mr Mitchell added.
British Foreign Secretary David Cameron said he had spoken with his Israeli counterpart Israel Katz to underline that the deaths were "completely unacceptable".
"Israel must urgently explain how this happened (and) make major changes to ensure safety of aid workers on the ground," he added.
"These were people who were working to deliver life-saving aid to those who desperately need it," Mr Cameron said on social media.
"It is essential that humanitarian workers are protected and able to carry out their work."
Earlier, Tánaiste and Minister for Foreign Affairs Micheál Martin said "full accountability" is needed following the Israeli air strike in Gaza which killed seven aid workers from a food charity.
In a post on social media, Mr Martin said he was "appalled" by the deaths of the humanitarian workers from World Central Kitchen.
He added that the incident "again underlines the need for an immediate ceasefire to protect civilians and allow full humanitarian access".
Appalled by the deaths of humanitarian workers in an Israeli strike, killed providing lifesaving aid to the people of Gaza.
— Micheál Martin (@MichealMartinTD) April 2, 2024
Full accountability is needed.
This again underlines the need for an immediate ceasefire to protect civilians and allow full humanitarian access.
It comes after EU foreign policy chief Josep Borrell earlier condemned the strike, and called for an inquiry.
"I condemn the attack and urge an investigation. Despite all the demands to protect civilians and humanitarian workers, we see new innocent casualties," Mr Borrell wrote on X, formerly Twitter.
Citizens from Australia, Britain and Poland were among those working for Spanish celebrity chef Jose Andres' WCK, the NGO said.
The WCK delivers food relief and prepares meals for people in need. It said last month it had served more than 42 million meals in Gaza over 175 days.
"This is not only an attack against WCK, this is an attack on humanitarian organisations showing up in the most dire of situations where food is being used as a weapon of war," said Erin Gore, chief executive of World Central Kitchen.
"This is unforgivable."
Australian Prime Minister Anthony Albanese confirmed the death of 44-year-old Australian aid worker Lalzawmi 'Zomi' Frankcom and said his government had contacted Israel to demand those responsible be held accountable.
"This is a human tragedy that should never have occurred, that is completely unacceptable and Australia will seek full and proper accountability," he said at a news conference.
Mr Albanese said innocent civilians and those doing humanitarian work needed to be protected and reiterated his call for a sustainable ceasefire in Gaza along with more aid to help those suffering from "tremendous deprivation".
Poland's foreign ministry expressed condolences to the family of a Polish volunteer killed in the strike.
"We extend our deepest condolences to the family of the volunteer who was providing aid to the Palestinian people in the Gaza Strip," the ministry said in a post on X.
"Poland objects to the disregard for international humanitarian law and the protection of civilians, including humanitarian workers."
The president of the city of Przemysl, in southeastern Poland, identified the volunteer as Damian Sobol.
"Yesterday, our colleague, resident of Przemysl, volunteer, member of the World Central Kitchen team - Damian Sobol, was killed in a rocket attack by Israeli forces on a humanitarian convoy delivering food in the Gaza Strip," he wrote on Facebook.
"There are no words to describe what people who knew this fantastic guy feel at this moment... May he rest in peace."
Polish Foreign Minister Radoslaw Sikorski said he had asked the Israeli ambassador to Poland for "urgent explanations".
"I personally asked the Israeli ambassador Yacov Livne for urgent explanations," Mr Sikorski said on social media, adding that he had offered "condolences to the family of our brave volunteer" and saying Poland would open its own inquiry into the aid worker's death.
Speaking in Amman, Spanish Prime Minister Pedro Sanchez said that Israel must clarify the circumstances surrounding the deaths of the people working for WCK.
"I expect and demand that the Israeli government clarify as soon as possible the circumstances of this brutal attack that has taken the lives of seven aid workers who were doing nothing but helping," he said during a visit to the Jabal el-Hussein Palestinian refugee camp in neighbouring Jordan.
'Ripple of concern'
UNICEF's Communications Specialist in Gaza Tess Ingram has said the attack on the World Central Kitchen’s aid operation has sent a "ripple of concern through humanitarian workers on the ground".
However, she said that "ultimately" aid workers will "stay and deliver" for those in Gaza.
Speaking on RTÉ's Drivetime, Ms Ingram, who is in Rafah, said: "We can hope this horrible tragedy sharpens people's attention on what's happening daily to people in Gaza."
She said facilitated missions often face enormous challenges such as delays at crossing points, staff being interrogated, danger and death.
"I think it's a clear indication that either way the system is failing" humanitarian workers," she said.
Ms Ingram added that humanitarian organisations are "not getting the safety assurances" that they need.
