The New York-based rights group said in a report Tuesday that in each case the aid groups had provided their coordinates to Israeli authorities to ensure their safety. It says no warning was given before the strikes, which also wounded at least 16 people.

The U.N. Office for the Coordination of Humanitarian Affairs says over 250 aid workers have been killed since the start of the war, mostly Palestinian employees of the U.N. agency for Palestinian refugees, the main provider in the territory.

The Israeli occupation army says it is investigating after a member of a U.N. security team was killed while driving in the southern city of Rafah on Monday. The army claimed the shooting occurred in an “active combat zone” and that it had not been informed of the vehicle’s route.

The U.N. said one of its international staff was killed and another wounded on Monday when their marked U.N. vehicle was fired upon. It did not say who was responsible or provide the nationalities of the staffers.

Human Rights Watch says the eight incidents it documented “reveal fundamental flaws with the so-called deconfliction system, meant to protect aid workers and allow them to safely deliver life-saving humanitarian assistance in Gaza.”

Belkis Wille, associate crisis, conflict, and arms director at Human Rights Watch, said “Israel’s allies need to recognize that these attacks that have killed aid workers have happened over and over again, and they need to stop.”

Israel came under heavy criticism last month after launching a series of strikes that killed seven aid workers with World Central Kitchen, the charity founded by celebrity chef José Andrés.

In another incident, on 8 January, an Israeli projectile pierced the side of a building in which more than 100 Médecins Sans Frontières (MSF) staff and their families were sheltering in Khan Younis. The five-year-old daughter of an MSF worker was killed and four people were injured.

HRW said MSF had told it that its staff saw no military targets in the area and received no warning of the attack.

Aid organizations say their ability to deliver life-saving assistance to Gaza’s 2.3 million people has been hampered by Israeli restrictions, ongoing fighting and the difficulty of coordinating movements with the Israeli military. The U.N. says severe hunger is widespread in Gaza and that the northern part of the territory is experiencing “full-blown famine.”

Human Rights Watch says Israel did not respond to a request for information on the strikes sent on May 1. The army did not respond to a request for comment from The Associated Press.