An estimated 280,000 Gazans have been newly displaced since the intensification of hostilities over two weeks ago, with some of them forced to move into overcrowded, flea- and mite-infested shelters, according to UN humanitarians on Thursday.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said more Israeli displacement orders were issued, again forcing people to flee in search of safety.

"Increasing numbers of people are moving into the remaining shelters which are already overcrowded," OCHA said. "Infestations of fleas and mites are reported, causing skin rashes and other health issues."

The office said the aid blockade makes it difficult to tackle the problem due to the lack of materials available in Gaza to improve hygiene conditions.

OCHA said the United Nations and its humanitarian partners continue to respond to the immense needs of the population as the conditions allow. The month-long blockade on the entry of all humanitarian aid and essential goods deprives the population of basic needs. Food assistance inside Gaza is rapidly running out.

However, the office said food security partners have so far been able to deliver more than 900,00 hot meals daily.

OCHA urged immediately reopening the crossings for cargo and humanitarian aid to enter Gaza.