Hamas on Tuesday blasted Israel's refusal to allow some 2,000 coronavirus vaccine doses destined for Gaza health workers through its blockade of the territory as a "violation" of international law.
The Palestinian Authority, based in the Israeli-occupied West Bank, had planned to send the Russian Sputnik V doses through Israel to Gaza, a separate territory run by Islamist movement Hamas.
But on Monday evening, the PA health ministry said Israel had blocked the delivery.
Israel's move marked "a real crime and a violation of all international laws and humanitarian standards," Hamas spokesman Hazem Qassem said.
COGAT, the Israeli military department that runs civil affairs in the occupied Palestinian territories, said Monday that the PA had requested to transfer 1,000 vaccine doses to Gaza but that "this request is waiting for a political decision".
The Palestinian Authority on Tuesday urged the World Health Organization to "condemn Israel" for the obstruction.
The PA called on the WHO and other international organisations "to hold (Israel) fully responsible for the dangers arising from preventing the entry of vaccines into the Gaza Strip," spokesman Ibrahim Melhem said.
The PA said Monday that its own vaccination campaign for the general public had been pushed back due to a delay in deliveries.
It had been anticipating a shipment by the middle of this month, enabling it to start vaccinating the general public in the West Bank while sharing stock with Hamas.
The PA is expecting some two million doses ordered from various manufacturers, in addition to vaccines from the UN-backed Covax programme, set up to help less wealthy nations procure vaccines.
It began inoculating frontline healthcare workers earlier this month with an initial procurement of 10,000 doses of the Sputnik V vaccine, as well as several thousand doses of the Moderna product.
Israel, which is carrying out one of the world's fastest vaccination campaigns per capita, has faced international calls to share its stocks with Palestinians living in the occupied West Bank and blockaded Gaza.