Israel's airstrike in the occupied West Bank on Friday has raised the death toll from its large-scale military operation, now in its third day, to at least 19.

A top United Nations aid official has questioned "what has become of our basic humanity" as the conflict continues in Gaza and humanitarian efforts struggle to keep up.

The U.N. has warned that the operation, which Israel began in the occupied West Bank early Wednesday, is "fueling an already explosive situation" and has urged Israel to end it.

In the U.S., Vice President Kamala Harris pledged that she would not change Washington's policy of supplying weapons to Israel if elected president in November.

However, she stressed that it is time to "end this war."

Israel has described its raids on towns and refugee camps across the northern West Bank as "counterterrorism" operations.

The raids have killed at least 19 Palestinians since Wednesday, according to the military and the Palestinian Health Ministry.

The military alleged that it killed three Hamas members in an airstrike near the northern city of Jenin on Friday.

Also, witnesses report that the forces targeted a civilian car in the town of Zababdeh, southeast of Jenin.

Israeli troops withdrew from other West Bank towns late Thursday, but chaos continued around Jenin.

Agence France-Presse (AFP) journalists reported loud explosions from the city's refugee camp and thick plumes of smoke rising from the area.

Vaccination 'pauses'

In Gaza, Israeli artillery pounded western areas of Gaza City early Friday, an AFP journalist said.

A medical source at the southern Al-Nasser Hospital reported that an Israeli strike killed three people near the southern city of Khan Younis.

The World Health Organization (WHO) said Israel had agreed to at least three days of "humanitarian pauses" in parts of Gaza, starting Sunday, to facilitate a vaccination drive after the first case of polio in a quarter of a century was recorded in the territory.

Israeli Prime Minister Benjamin Netanyahu said the measures were "not a cease-fire" in the nearly 11-month-old conflict triggered by Hamas' Oct. 7 incursion.

The Israeli assault has caused significant destruction, especially in Tulkarem, whose governor Mustafa Taqatqa described the raids as "unprecedented" and a "dangerous signal."

The Palestinian Prisoners' Club advocacy group said at least 45 people had been detained in the West Bank since Wednesday.

An Israeli military spokesperson said, "10 wanted individuals were arrested."

Violence has surged in the West Bank since Hamas' Oct. 7 incursion on Israel, which triggered the latest conflict in Gaza.

The U.N. said on Wednesday that at least 637 Palestinians had been killed in the territory by Israeli troops or settlers since the Gaza conflict began.

Nineteen Israelis, including soldiers, have been killed in Palestinian attacks or during military operations over the same period, according to Israeli official figures.

Basic sense of humanity

In Gaza, the Israeli military said Thursday it had "eliminated dozens" of Hamas members in a day of combat and strikes.

Israeli shelling in the Jabalia refugee camp killed two people on Friday, the civil defense agency in the Hamas-ruled territory said.

The U.N. had to halt the movement of aid and aid workers within Gaza on Monday due to a new Israeli evacuation order for the Deir el-Balah area, which had become a hub for its workers.

"More than 88% of Gaza's territory has come under an (Israeli) order to evacuate at some point," said Joyce Msuya, acting head of the U.N. humanitarian office.

She said civilians are being forced into just 11% of the Gaza Strip, already one of the most densely populated territories in the world before the war.

"What we have witnessed over the past 11 months ... calls into question the world's commitment to the international legal order designed to prevent these tragedies," Msuya said.

"It forces us to ask: What has become of our basic sense of humanity?"

Hamas's Oct. 7 incursion resulted in the deaths of 1,199 people.

The Palestinian group also seized 251 hostages, 103 of whom are still captive in Gaza.

Israel's retaliatory military campaign has killed at least 40,602 people in Gaza, according to the territory's Health Ministry.

The U.N. rights office says most of the dead are women and children.

The war has devastated Gaza, repeatedly displaced most of its 2.4 million people, and triggered a humanitarian crisis.

In central Gaza, some Palestinians returned to parts of Deir el-Balah after the military amended a previous evacuation order.

Mohamed Abu Thuria told AFP he had "found massive destruction everywhere."

Another displaced Gazan back in Deir el-Balah, Ibrahim al-Tabaan, said: "We lost everything."