CAIRO / RAMALLAH / BEIRUT - The United Nations, in collaboration with Palestinian health authorities, began to vaccinate 640,000 children in the Gaza Strip on Sunday, with Israel and Hamas agreeing to brief pauses in their 11-month war to allow the campaign to go ahead.

The World Health Organisation (WHO) confirmed last month that a baby was partially paralyzed by the type 2 polio virus, the first such case in the territory in 25 years.

The campaign began on Sunday in areas of central Gaza, and will move to other areas in coming days. Fighting will pause for at least eight hours on three consecutive days.

The WHO said the pauses will likely need to extend to a fourth day and the first round of vaccinations will take just under two weeks.

'Complex campaign'

"This is the first few hours of the first phase of a massive campaign, one of the most complex in the world," said Juliette Touma, communications director of UNRWA, the UN Palestinian refugee agency.

"Today is test time for parties to the conflict to respect these area pauses to allow the UNRWA teams and other medical workers to reach children with these very precious two drops. It’s a race against time," Touma told Reuters.

Israel and Hamas, who have so far failed to conclude a deal that would end the war, said they would cooperate to allow the campaign to succeed.

WHO officials say at least 90 percent of the children need to be vaccinated twice with four weeks between doses for the campaign to succeed, but it faces huge challenges in Gaza, which has been largely destroyed by the war.

"Children continue to be exposed, it knows no borders, checkpoints or lines of fighting. Every child must be vaccinated in Gaza and Israel to curb the risks of this vicious disease spreading," said Touma.

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Meanwhile, Israeli forces continued to battle Hamas-led militants in several areas across the Palestinian enclave. Residents said Israeli army troops blew up several houses in Rafah, near the border with Egypt, while tanks continued to operate in the northern Gaza City suburb of Zeitoun.

On Sunday, Israel recovered the bodies of six hostages from a tunnel in southern Gaza where they were apparently killed not long before Israeli troops reached them, the military said.

On Saturday, the Israeli army killed two Palestinians in Jenin, northern West Bank, as Israel's military operation in the city entered its fourth day, the Palestinian Health Ministry reported.

The ministry identified the victims as Amjad Mustafa Ibrahim Saleh and Muhammad Amin Talal Abdullah, but did not provide further details.

The Palestinian Red Crescent Society reported that Israeli forces obstructed its staff from transporting the bodies after they reached the Jenin refugee camp. The society also noted that its teams are evacuating emergency cases from Jenin Government Hospital to Al-Razi Hospital due to a power outage.

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The Palestinian government has warned of possible shutdowns in some hospital departments in Jenin and expressed concern for dialysis patients. It also stated that it is pursuing legal action to hold Israel accountable for its "crimes" and is working to repair the damage inflicted by the Israeli army.

Palestinian Prime Minister Mohammad Mustafa has called on international health organizations and the Red Cross to pressure for the lifting of the hospital blockade and to address disruptions to ambulances and medical teams.

'Danger of escalation'

Lebanon's Foreign Ministry condemned the ongoing Israeli military operations in the West Bank areas of Jenin, Tulkarm, and Tubas, warning of the "danger of escalation."

In a statement, the ministry said the attacks in the West Bank had resulted in "deaths and injuries among many unarmed civilians," coinciding with the ongoing Israeli military operations in the Gaza Strip.

The statement highlighted the "continued forced evictions and displacement of West Bank residents," calling these actions "a flagrant violation of international humanitarian law and United Nations resolutions."

READ MORE: Israeli assault in the West Bank kills at least nine, Palestinian officials say

The ministry also cautioned against "the recent escalation" and the ongoing "provocative violations" at holy sites in Jerusalem, specifically referencing Israel's National Security Minister Itamar Ben-Gvir's statements advocating for the establishment of a Jewish synagogue at the Al-Aqsa Mosque compound.

Since Wednesday, Israel has conducted a large-scale raid across the northern West Bank, stating that the operation aims to prevent future attacks against Israel.

Tensions have escalated int he West Bank since the outbreak of the war between Israel and Hamas in the Gaza Strip on Oct 7, 2023. The Palestinian Health Ministry reports that more than 660 Palestinians have been killed by the Israelia army in the West Bank.