GENEVA: The World Health Organisation said on Wednesday that `intense bombardment` and `escalating violence` in northern Gaza had forced it to postpone the final phase of a child polio vaccination drive.

The necessary second round of vaccinations has been completed in central and southern Gaza, and was to begin on Wednesday in the north. But the WHO said it had been `compelled to postpone` the bid to give 119,279 children in northern Gaza a second vaccine dose.

Israel launched a major air and ground assault in northern Gaza this month, vowing to stop Hamas from regrouping in the area.

The vaccination campaign was called off `due to the escalating violence, intense bombardment, mass displacement orders, and lack of assured humanitarian pauses across most of northern Gaza,` the UN health agency said.

`The current conditions, including ongoing attacks on civilian infrastructure, continue to jeopardise people`s safety and movement in northern Gaza, making it impossible for families to safely bring their children for vaccination,` and for health workers to operate, it added.

The vaccination drive began after the Gaza Strip confirmed its first case of polio in 25 years. The conflict has left most medical facilities and Gaza`s sewage system in ruins. Typically spread through sewage and contaminated water, poliovirus is highly infectious.

The WHO says a minimum of two separate doses of oral vaccine are needed to interrupt poliovirus transmission.-AFP