The head of the UN agency for Palestinian refugees (UNRWA) called on Tuesday for countries to back an independent investigation into alleged killings and detentions of its staff and damage to its premises once the Israel-Hamas conflict ends.

UNRWA has accused Israel of targeting its facilities during more than seven months of conflict in the Gaza Strip, and said 182 of its staff there had been killed and more than 160 of its shelters hit, resulting in the deaths of hundreds of people fleeing Israeli bombardment.

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.

UNRWA is the biggest humanitarian aid provider in Gaza where its 13,000 staff there also run schools and social services for the refugees who make up the majority of Gazans.