LONDON/GENEVA (Reuters) -The World Health Organization cancelled another planned medical aid mission to Gaza on Wednesday over security concerns, the sixth such cancellation in two weeks.

WHO Director-General Tedros Adhanom Ghebreyesus said it was the sixth mission to northern Gaza cancelled by the U.N. agency because requests to visit had not been approved or assurances over security provided since its last visit, on 26 December.

“Intense bombardment, restrictions on movement, fuel shortage and interrupted communications make it impossible for WHO and our partners to reach those in need,” he told a virtual press conference from Geneva. “We call on Israel to approve requests by WHO and other partners to deliver humanitarian aid.”

The Israeli offensive launched in the wake of a deadly rampage by Hamas in southern Israel on Oct. 7 has displaced most of Gaza’s 2.3 million population, left many homes and civilian infrastructure in ruins, and caused acute shortages of food, water and medicine. Fighting has intensified recently despite a pledge this week to scale down the war.

The WHO said on Wednesday only 15 hospitals in Gaza remain functional, even partially.

(Reporting by Jennifer Rigby and Gabrielle Tétrault-Farber; Editing by Elaine Hardcastle, William Maclean)