A Japanese member of the UN agency for Palestinian refugees has expressed shock and outrage at the deaths of staff of an international non-profit organization in an Israeli airstrike in Gaza.

Seita Akihiro, head of the healthcare division of the United Nations Relief and Works Agency for Palestine Refugees in the Near East, or UNRWA, spoke with NHK online from Rafah in southern Gaza.

Seven members of the World Central Kitchen were killed in an airstrike on Tuesday. The group is delivering aid in the area.

Israeli Prime Minister Benjamin Netanyahu admitted that Israeli forces carried out the strike. He said it was unintentional and that efforts to prevent a recurrence will be made.

In Tuesday's interview, Seita noted that support groups and UN organizations obtain permission from Israel when they move in areas near combat zones in Gaza.

"What should not happen has happened. I'm shocked and outraged," Seita said.

He also explained the devastating situation in Gaza, with 800 people sharing one toilet and 3,000 using one shower at shelters.

He said sanitary conditions are so poor that many people are suffering from hepatitis, diarrhea and respiratory diseases. He stressed the serious shortage of food and medicines such as antibiotics to treat children.

Seita called for an immediate humanitarian ceasefire to improve the situation.

The Israeli prime minister's office announced on Tuesday that Israel and mediator countries ended talks in Egypt on a ceasefire and the release of hostages. It said they have drawn up proposals to be presented to Hamas by the mediators.