The head of the UN Agency for Palestinian Refugees (UNRWA) has called for countries to back an independent investigation into alleged killings and detentions of its staff and damage to its premises once the Israeli bombardment of Gaza ends, Reuters reports.

After briefing UN member states in Geneva, UNRWA Commissioner-General Philippe Lazzarini told reporters he wanted the countries to back an independent investigation “to look into this blatant disregard of the United Nations in order to avoid that this becomes also in the future the new standard.”

Lazzarini said Israel blocked him from entering Gaza last month, and that he plans to visit again on Sunday. He voiced hope that Israel would let him in.

Food and other humanitarian aid supplies to Gaza have improved in April, but there is still far from enough to reverse the trend towards famine, he said.