JERUSALEM — The Israeli military fired a missile at the lead vehicle of an aid convoy in Gaza, killing four Palestinians, the convoy’s organizers said. The military said it struck after identifying weapons aboard one of the trucks, adding that the four Palestinians were armed and hadn’t been included in the coordinated travel plan.

The military also said it killed a top Hamas commander and two other fighters Friday as its large-scale operations in the West Bank continued into a third day.

The convoy, organized by the D.C.-based nonprofit American Near East Refugee Aid, known as Anera, was delivering medical supplies and fuel to an Emirati-run hospital in Rafah. Its route was coordinated with the Israel Defense Forces.

Both the IDF and Anera noted, however, that four armed Palestinians who joined the convoy while it was in transit had not been vetted. The IDF said it carried out its strike after confirming the presence of weapons in one of the vehicles.

In a separate statement, Anera said the Palestinians joined the convoy out of concern that the route ahead was dangerous and were not viewed as a threat. The nonprofit added that Israel did not communicate its plans to strike the vehicle to Anera and described the dead as “community members” with security experience.

“According to all the information we have, this is a case of partners on the ground endeavoring to deliver aid successfully,” said Anera president and CEO Sean Carroll.

In an earlier statement to The Washington Post, Anera said that five people had been killed in Israel’s strike. Later Friday, the nonprofit revised the toll down to four.

The deadly strike in southern Gaza on Thursday comes just days after a World Food Program truck was fired on in the enclave and amid an increasingly strained environment in which humanitarian organizations are operating.

Humanitarian groups providing desperately needed aid in Gaza have repeatedly come under attack during the war, raising concerns about the system used to coordinate routes and the IDF’s approach to the conflict. According to the United Nations, more than 280 humanitarian workers have been killed since the war in Gaza began in October. The U.N. Office for Coordination of Humanitarian Affairs said Friday that the number of planned humanitarian missions for August that had been denied by Israel had nearly doubled since July.

Seven World Central Kitchen aid workers were killed in an Israeli airstrike in April, making global headlines. Israeli forces at the time also believed, incorrectly, that militants were present in the convoy.

An Anera employee, Mousa Shawwa, a logistics coordinator in Gaza, was killed March 8 by an Israeli airstrike while he was in a deconflicted shelter, Carroll told The Washington Post at the time. The relief worker’s 6-year-old son, Karim, died 10 days later from injuries suffered during the attack, he said.

Thursday’s incident is one of several such attacks this week. In remarks to the United Nations Security Council on Thursday, U.S. representative Robert Wood referred to an incident that occurred Sunday, according to U.N. officials, in which he said the IDF fired toward a UNICEF vehicle.

On Tuesday, at least 10 rounds were fired into a World Food Program vehicle, which the United Nations blamed on Israel and prompted WFP to temporarily suspend staff movement across Gaza. Wood said the Biden administration was “deeply alarmed” by Tuesday’s shooting and urged Israel to “immediately rectify the issues within their system that allowed this to happen.”

In the West Bank, the IDF said its forces killed Wesam Khazem, the head of Hamas activities in Jenin, in a brief firefight. Two others were struck by supporting aircraft when they fled the car they were traveling in.

Hamas, in a statement, confirmed the three deaths, and witnesses posted photographs of the bombed vehicle.

The IDF said real-time intelligence allowed them to pinpoint Khazem’s driving route Friday on a road south of Jenin. The 28-year-old was the senior Hamas operative in the city, according to the IDF and people in Jenin familiar with Khazem’s role in the militant group.

Israel said Khazem had played a direct role in multiple shootings and bomb attacks in the West Bank and described him as one of the IDF’s top targets.

Khazem’s uncle, Abu Nidal Al Khazem, said he had urged the young man to take his wife and two young daughters out of the West Bank earlier this year as IDF raids were intensifying. Both of Khazem’s parents are in Norway, the uncle said, and Khazem has a Norwegian passport. The younger man refused.

“He is very much connected to the camp and to his cousins. They were very close to each other,” Abu Nidal al Khazem said. “He was not listening to me.”

The Norwegian Embassy in Washington did not immediately respond to a request to confirm Khazem’s status.

Khazem’s killing follows the death Thursday of another prominent Palestinian militant commander, Mohamed Jaber, also known as Abu Shuja’a. Jaber, 26, who headed the Tulkarm Battalion, an umbrella group led by Palestinian Islamic Jihad, was killed when IDF forces raided the mosque where he was hiding in the Nur al-Shams camp.

The IDF said Friday that Israeli forces have killed 20 people — whom they described as “terrorists” — in airstrikes and “exchanges of fire” since the incursion began early Tuesday in multiple West Bank locations, including sites in Jenin, Tulkarm and the al-Fara’a refugee camp.

In its largest actions in the Palestinian territory since the Oct. 7 attacks by Hamas, hundreds of Israeli troops moved on the areas, sometimes with air cover. Israel said the attacks are meant to root out militant cells and destroy their infrastructure and weapons.

Thousands of civilians have been affected, with families trapped in battle-shaken neighborhoods, often without water, electricity or internet. Israeli combat bulldozers have plowed many of the area’s streets to rubble to clear possible booby traps.

“The situation is catastrophic,” Ahmad Zahran, deputy director of the Red Crescent in Tulkarm, told The Post on Thursday.

The IDF said it concluded operations in al-Fara’a on Thursday, while reports from Tulkarm’s two refugee camps said the scene was quiet. The military remained active in Jenin. The IDF has said it could continue the actions for several days.

The United Nations said it had been forced to suspend support services for refugees in several parts of the West Bank. “Tens of thousands of people in four refugee camps have been impacted by this operation, including through destruction of public and private infrastructure,” Philippe Lazzarini, the head of the U.N. Relief and Works Agency for Palestine Refugees, said in a tweet Friday.

Here’s what to know

• The World Health Organization said Israel has agreed to successive “humanitarian pauses” in military operations in Gaza, beginning Sunday, to allow more than 640,000 children to be given oral polio vaccinations after an outbreak of the virus. The pauses, from 6 a.m. to 3 p.m., will last for at least three days in three separate zones, beginning in central Gaza and then moving to the south and the north, according to the WHO.

• Vice President Kamala Harris told CNN in an interview that “far too many innocent Palestinians have been killed,” while also stressing Israel’s right to defend itself. In her first major interview since she rose to the top of the Democratic ticket, she did not fully answer whether she would be open to withholding U.S. weapons shipments to Israel should she be elected president, instead pointing to her work with President Joe Biden to secure a cease-fire and hostage deal.

• At least 40,602 ​​people have been killed and 93,855 injured in Gaza since the war started, according to the Gaza Health Ministry on Thursday. It does not distinguish between civilians and combatants but says the majority of the dead are women and children. Israel estimates that about 1,200 people were killed in Hamas’ Oct. 7 attack, including more than 300 soldiers, and it says 339 soldiers have been killed since the start of its military operations in Gaza.

Suliman reported from London, Ables from Seoul and Pietsch from Washington.