United Nations, Sep 5 : The first three-day phase of the first round of polio vaccinations has reached 187,000 children under 10 years of age in Gaza's central zone, UN humanitarians said.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said on Wednesday that the campaign now turns to Gaza's southern zone for three days, beginning on Thursday, and the northern zone will follow, Xinhua news agency reported.

More than 640,000 children are targeted to receive two oral doses of the vaccine, each dose four weeks apart.

OCHA said World Health Organisation Director-General Tedros Adhanom Ghebreyesus reported that health workers had vaccinated 187,000 children since Sunday.

The UN Children's Fund (Unicef) said regional pauses in the conflict are necessary for the remaining phases of the campaign, "otherwise we will fail to protect the children of Gaza and place other children at risk".

The campaign was launched after a 10-month-old was partially paralysed with polio.

OCHA said 510 teams were deployed across central Gaza for the vaccination effort, with 40 health partners participating -- 17 operating health service points to administer vaccinations and 23 informing communities about the campaign.

Health experts have warned of disease outbreaks in the territory, where the vast majority of people have been displaced, often multiple times, and where hunger is widespread.

Hundreds of thousands of people are crammed into squalid tent camps with few if any public services.

The vaccinations were being undertaken even as fighting continued in Gaza, with the Hamas-controlled Gaza Health Ministry saying 42 people had been killed over the past 24 hours and 40,861 people since the war began.

The head of the UN's main agency for Palestinian refugees, Philippe Lazzarini, wrote on Wednesday: "Great progress! Every day in the Middle Areas of #Gaza, more children are getting vaccines against #Polio."

"While these polio 'pauses' are giving people some respite, what is urgently needed is a permanent ceasefire, the release of all hostages and the standard flow of humanitarian supplies including medical and hygiene supplies (into Gaza)," Lazzarini posted on X.

Despite the success of the polio campaign, diplomatic efforts to secure a permanent ceasefire, release hostages held in Gaza and return many Palestinians jailed by Israel, have faltered.

The Israeli Prime Minister, Benjamin Netanyahu, insisted on Monday that Israeli troops would remain in the Philadelphi corridor on the southern edge of Gaza bordering Egypt, one of the main sticking points in reaching a deal.

However, on Wednesday, Ron Dermer, the country's strategic affairs Minister, appeared to suggest that Israel may be prepared for a full withdrawal in a negotiated second phase of any deal.

Speaking to Bloomberg, Dermer said: "In phase one, Israel is going to stay on that line until we have a practical solution on the ground that can convince the people of Israel... that what happened on October 7 will not happen again. That Hamas will not rearm."

"And once you've concluded those negotiations, while you're in a ceasefire for phase one, in order to get to phase two and a permanent ceasefire, that's when you can discuss long-term security arrangements on the Philadelphi corridor."

Hamas, which wants any agreement ending the war to include a withdrawal of all Israeli forces from Gaza, says such a condition, among some others, would prevent an accord. Netanyahu says the war can only end when Hamas is eradicated.

The impasse is frustrating Israel's international allies and the 15 members of the UN security council, where Slovenia holds the presidency for September.

Slovenia's ambassador to the UN, Samuel Zbogar, said on Tuesday that patience was running out and the global body would probably consider taking action if a ceasefire could not be brokered soon.

/IANS