An immediate ceasefire is needed in the Gaza Strip as the enclave faces the additional threat of polio spreading, if the final phase of a vaccination campaign there continues to be delayed, an UN agency warned on Thursday.

The third and final phase of the polio vaccination campaign, which was set to start on Wednesday in Gaza, had to be postponed due to the escalating violence, intense bombardment, mass displacement orders, and lack of assured humanitarian pauses.

“It is imperative to stop the polio outbreak in Gaza before more children are paralysed and the virus spreads,” said Louise Wateridge, spokesperson for the UN Agency for Palestine Refugees (UNRWA).