At least 12 United Nations Relief and Works Agency (UNRWA) staff members have been killed during Israel’s fierce and indiscriminate bombardment of the Gaza Strip, which entered its sixth day on Thursday.
Among those killed were a gynaecologist, an engineer and a psychological counsellor.
Five teachers and three operations workers were also killed, according to UNRWA spokesman Stephane Dujarric. The latest casualty is yet to be identified.
Some were killed in their homes with their families in the besieged enclave, where infrastructure - including a UNRWA school - and residential buildings have been destroyed in Israeli attacks, Dujarric said.
Jennifer Austin, the Director of Operations in Gaza, expressed grief at the staff members' loss and stressed "the need to protect civilians and United Nations staff at all times during conflict", while calling for "an end to the fighting to prevent further loss of life", in a statement.
The agency also stressed "the necessity of protecting civilians in accordance with the laws of war".
The UNRWA agency serves around 5.9 million Palestinian refugees in the West Bank, Gaza, Jordan, Syria and Lebanon, and was established over 70 years ago following the mass expulsion and displacement of Palestinians after the creation of Israel in 1948.
The agency provides aid and development to Palestinian refugees, supplying basic education, employment, social services, and health care.
In recent years, however, the agency has been faced with financial issues due to a severe lack of funding, as major countries cut back on donations, with many of its workers going on strikes to demand increased pay.
Separately, 30 students at UNRWA schools have been killed in the bloodshed, with eight wounded, Dujarric confirmed. At least 326 children in Gaza have been killed so far.
Israel has relentlessly bombarded the already-besieged enclave since Saturday, in response to an unprecedented cross-border attack carried out by Hamas - called "Al-Aqsa Flood" - on Saturday.
Israeli assaults have killed at least 1,354 Palestinians, according to the Gaza Health Ministry, with 6,000 people injured - many critically.
Hamas’ assault killed at least 1,300 people in Israel, including a number of foreign nationals.
Gaza is a densely-populated enclave home to 2.3 million residents and has been subject to an almost 16-year blockade imposed by Israel, plunging its residents into poverty and restricting travel and access to basic necessities, such as medicine and medical equipment.
The Israeli government has also vowed to cut off water, food and fuel from Gaza, until Hamas releases all the Israelis it captured on Saturday.