JERUSALEM (JTA) — The United Nations is preparing to investigate the targeting of its schools in Gaza during Israel’s recent operation in Gaza, U.N. Secretary-General Ban Ki-moon told an Arabic newspaper.

Several United Nations workers were kicked in airstrikes on the schools, which were housing internally displaced Palestinians. Weapons were found by the U.N. to be stored by Gaza terror groups in at least three U.N. schools.

The investigation is separate from a U.N. Human Rights Council panel investigating possible war crimes committed by Israel during the 50 days of Operation Protective Edge, Ban told the London-base Arabic Al-Hayat newspaper.

Israel has said soldiers were responding to rocket fire emanating from next to or inside the schools’ yards.

The investigation would not begin until the end of the UNHCR investigation led by Canadian judge William Schabas.

Ban told the newspaper that he already told the Israelis about the future probe, which will look into “the killing and wounding of United Nations personnel and the destruction of its facilities and to hold accountable those responsible,” as well as to investigate the storage of weapons in some of these facilities.