Israel’s military bombed a school housing displaced Palestinians in central Gaza, killing at least 18 people, including six staff members of the United Nations agency for Palestinian refugees (UNRWA).

The strike on Wednesday that flattened part of the UN-run facility in the Nuseirat refugee camp was condemned by several countries and UN agencies.

Some 12,000 displaced Palestinians, most of them women and children, were sheltering at al-Jaouni, according to UNRWA, when Israeli forces carried out two air attacks on the building.

“Endless and senseless killing, day after day,” UNRWA Commissioner-General Philippe Lazzarini said. “Humanitarian staff, premises and operations have been blatantly and unabatedly disregarded since the beginning of the war.”

The death of six staff members takes the number of UNRWA employees killed in Gaza to at least 220.

The Palestinian Civil Defence spokesman in Gaza, Mahmoud Basal, posted on the Telegram messaging app that the school was bombed for the fifth time and more than 18 people were wounded.

Tedros Adhanom Ghebreyesus, the director-general of the World Health Organization, said “the carnage in Gaza must stop”.

“No words can reflect the true horror and loss of life in Gaza,” he wrote on X. “Hospitals, schools and shelters have been repeatedly bombarded, resulting in deaths of civilians and humanitarians.”

Many school buildings have been repurposed to shelter displaced families across the besieged Gaza Strip, as a majority of the enclave’s 2.4 million people have been repeatedly uprooted by the war.

Israeli forces have struck several such schools in recent months, claiming that Hamas operates from these places and hides among civilians. The Palestinian group has denied the charges.

The Israeli military said in a statement that it had conducted a “precise strike” on a Hamas command and control centre within the al-Jaouni compound. It did not elaborate on the outcome, but said “numerous steps” were taken to reduce the risk to civilians.