Doctors Without Borders on Thursday said an Israeli strike had killed one its workers, the 14th member of the medical charity to have died since the beginning of the war in Gaza.
The strike also wounded four others, one of whom was in a serious condition with shrapnel wounds, said a statement by the group, which goes by the French acronym MSF.
The United Nations and rights groups have frequently condemned the high death toll of humanitarians and aid workers in the Palestinian territory, as Israel pursues its offensive.
"The attack took place on a street where our teams were waiting to take a bus to the MSF field hospital in Deir el-Balah, Gaza," the charity said.
"All staff were wearing MSF vests, clearly identifying them as medical humanitarian workers."
The death of occupational therapist Omar Hayek, 42 comes less than two weeks after that of his colleague Hussein Alnajjar, also in Deir el-Balah, MSF said.
"Omar was a quiet man of profound kindness and utter professionalism," the charity said, adding that he had dedicated "his life to restoring strength and dignity to thousands of patients".
The Al-Aqsa Martyrs Hospital in Deir el-Balah said it had received nine bodies after several strikes on nearby areas.
According to AFP news agency, several corpses were seen, some wrapped in white shrouds, in the hospital morgue as relatives mourned nearby.
"We received word that some of our staff had been injured and taken to Al-Aqsa Martyrs Hospital," said Karin Huster, head of the MSF medical team in Gaza.
"When we arrived, we discovered that one of our colleagues had been killed, and four others wounded," she told AFP.
"The consequences will be tragic for their families and for our team. Enough killings -- whether targeted or not, this is unacceptable."
Israeli strikes killed at least 52 people across Gaza on Thursday, the territory's civil defence agency and hospitals said.
The civil defence agency said the deaths were caused "by continuous Israeli bombardments on the Gaza Strip since dawn," specifying that 10 people, including at least one child, were killed in Gaza City.
Several hospitals confirmed to AFP that they had received 10 bodies in Gaza City, 14 in central Gaza, and 28 in the territory's south.
They reported that some were killed in air strikes, others by drone fire and shootings.
Hamas's unprecedented attack on Israel on October 7, 2023 resulted in the deaths of 1,219 people, mostly civilians, according to Israeli figures.
Israel's military campaign since then has killed 66,225 Palestinians in Gaza, also mostly civilians, according to figures from the health ministry, which the United Nations considers reliable.