A Palestinian youth looks for salvageable items amid the rubble of the Kuhail building which was destroyed in an early morning Israeli air strike on Gaza on May 18 (Photo: AFP/ VNA)

WHO spokeswoman Fadela Chaib told a Geneva briefing that around 600 patients, including some with chronic conditions, needed to be referred outside of the Palestinian enclave since the start of the hostilities, but had been unable to due to crossing closures.

WHO has a presence on the ground, Chaib said, but was unable to confirm whether it currently had any access from the outside. Other aid agencies have complained about limited humanitarian access and drug supplies. Dozens of health centres were damaged during Israeli bombings earlier this month, prompting the WHO to warn that facilities risked being overwhelmed.