Six staff members of the UN relief agency for Palestinians, known as UNRWA, were killed in Israeli airstrikes in Gaza, UN Secretary-General Antonio Guterres said.

Israeli airstrikes hit a school-turned-shelter for around 12,000 people on Wednesday, and six UNRWA staff members were among those killed, Guterres said on X.

“What’s happening in Gaza is unacceptable,” he said. “These dramatic violations of international humanitarian law need to stop now.”