The United Nations on Monday condemned the "unacceptable" level of violence becoming commonplace against humanitarian workers, a record 280 of whom were killed worldwide in 2023.
And it warned that the Israel-Hamas war in Gaza is potentially fueling even higher numbers of such deaths this year.
"The normalization of violence against aid workers and the lack of accountability are unacceptable, unconscionable and enormously harmful for aid operations everywhere," Joyce Msuya, acting director of the UN's Office for the Coordination of Humanitarian Affairs (OCHA), said in a statement on World Humanitarian Day.
"With 280 aid workers killed in 33 countries last year, 2023 marked the deadliest year on record for the global humanitarian community," a 137 percent increase over 2022, when 118 aid workers died, OCHA said in the statement.
It cited the Aid Worker Security Database which has tracked such figures back to 1997.
The UN said more than half of the deaths in 2023, or 163, were aid workers killed in Gaza during the first three months of the war between Israel and Hamas, mainly in air strikes.
South Sudan, wracked by civil strife, and Sudan, where a war between two rival generals has been raging since April 2023, are the next deadliest conflicts for humanitarians, with 34 and 25 deaths respectively.
Also in the top 10 are Israel and Syria, with seven deaths each; Ethiopia and Ukraine, with six deaths each; Somalia at five fatalities; and four deaths both in Myanmar and the Democratic Republic of Congo.
In all the conflicts, most of the deaths are among local staff.
Despite 2023's "outrageously high number" of aid worker fatalities, OCHA said 2024 "may be on track for an even deadlier outcome."
As of August 9, 176 aid workers have been killed worldwide, according to the Aid Worker Security Database.
Since October, when Hamas-led militants launched a deadly raid into Israel, triggering the war, more than 280 aid workers have been killed in Gaza, the majority of them employees of the UN agency for Palestinian refugees, according to OCHA.
Against this backdrop, the leaders of multiple humanitarian organizations were to send a letter Monday to UN member states calling for the international community "to end attacks on civilians, protect all aid workers, and hold perpetrators to account."
Each year the United Nations marks World Humanitarian Day on August 19, the anniversary of the 2003 attack on its Baghdad headquarters.
The bombing killed 22 people including Sergio Vieira de Mello, the UN special representative to Iraq, and injured some 150 local and foreign aid workers.