The aim is to vaccinate some 640,000 children under the age of 10, the World Health Organization (WHO) says.

The roll-out will start in central Gaza on Sunday, with three consecutive daily pauses in fighting between 6am and 3pm local time.

It will then move to southern Gaza, where there will be another three-day pause, followed by northern Gaza.

According to UN officials, children who get the vaccine will need a second dose in late September.

Healthcare workers aim to achieve 95% vaccine coverage across the strip, the level needed to stop transmission of the virus within Gaza.

If this is not achieved there is an agreement for an additional humanitarian pause to allow a fourth day of vaccination.

About 1.3m doses of the novel oral polio vaccine type 2 (nOPV2) are already in Gaza, with 400,000 extra doses set to arrive soon.

Vaccinations will be carried out by UN staff and other local health workers. More than 2,000 health and community outreach workers have been trained to give the vaccine.

Vaccines will be available in hospitals, field hospitals and primary health centres.

According to the WHO, safe transport and refrigeration of the vaccines are crucial to the plan.