A fact-finding mission mandated by the United Nations has said that some of Israel’s strikes on Iran may have broken international humanitarian law, citing the killing of civilians in an apartment block and three aid workers in the capital Tehran, Reuters reports.

“Among those killed in Tehran were dozens of residents of an apartment complex and three humanitarian workers from the Iranian Red Cross, while damaged sites included a clinic for children with autism and a hospital in Kermanshah,” the investigative body said in a statement to journalists.

“This, and the reported lack of effective advance warning by Israel, which may affect the population’s ability to reach safety, raise serious concerns in relation to the principles of proportionality, distinction, and precaution under international humanitarian law.”