Right-wing Israeli protesters blocked trucks carrying food supplies that were headed into Gaza on Monday in the latest disruption to humanitarian relief for the war-torn Palestinian territory. The trucks were attacked by an Israel group called "Tsav 9" at the Tarqumiya checkpoint, a border crossing from the Israeli-occupied West Bank into Israel, west of the city of Hebron.

Sapir Sluzker Amran, an Israeli peace activist who opposed the protesters and witnessed the incident, told CBS News on Tuesday that the group that halted the trucks and then threw the food all over the ground were mainly Israeli settlers and extremists. 

"Most of them were settlers. They also live there, they are settlers in the settlements in the area," she said. "The common theme among all of them is that they are from the right wing Zionist groups. The religious nationalist stream, as we call it."

Videos and photos taken by Amran and shared with CBS News show protesters climbing onto an aid truck and throwing food packages onto the side of the road. Other images show protesters dumping flour out of large sacks from the vehicles.

U.S. calls attacks on aid "a total outrage"

At the White House media briefing on Monday, U.S. National Security Advisor Jake Sullivan slammed the attack.

"It is a total outrage that there are people who are attacking and looting these convoys coming from Jordan going to Gaza to deliver humanitarian assistance," he said. "We are looking at the tools we have to respond to this and we're also raising our concerns at the highest level of the Israeli government. It's something we make no bones about — we find it completely and utterly unacceptable."

U.K. foreign minister David Cameron also condemned the attack in a social media post and demanded that Israel hold all "attackers to account and do more to allow aid in," adding that he would be raising his concerns with the Israeli government over the incident.

Who was behind the attack on the aid convoy?

Tsav 9 is described by the Times of Israel newspaper as "a right-wing organization that opposes aid being sent to Gaza while hostages are still held there." 

The group shared images and video of the attack on the aid convoy Monday on its X account — which carries a line in Hebrew stating its mission to halt aid for Gaza until all Israeli hostages in the Palestinian territory are released. 

"No aid gets through — until the last of the kidnapped returns" the group's X account says.   

"They started a few months ago, they fundraise lots of money and they have many supporters in the government," Amran told CBS News, claiming the extremists are often tipped off about humanitarian aid convoys by Israeli military and police officials.

"They know, so they have information beforehand about when the trucks are coming, and they publish it on social media and they publish it on their groups, WhatsApp groups, and asking people to join and block or damage the aid," she said.

Amran said one member of the group slapped her Monday as she tried to stop the attack on the aid trucks. She said Israel Defense Forces  personnel at the scene did little to assist her.

"I was attacked by one of the settlers there in front of an IDF soldier that was sitting, standing very close to us — like maybe, I don't know, less than a meter, and saw that he slapped me really hard," she said. "They [the IDF] just protected him and kind of took him to the side."  

The Israel Police force said the Monday attack on the aid convoy was under investigation and that "multiple suspects" had been detained. 

COGAT, the Israeli agency responsible for policy in the Palestinian territories, did not immediately respond to a CBS News request for comment on the incident in the West Bank.

Rights group says 8 Israeli strikes have hit aid workers or sites

The attack highlighted the risks of humanitarian aid work for Palestinians as the war between Israel and Hamas rages in Gaza.

On Tuesday, the U.S.-based organization Human Rights Watch released a report accusing the IDF of at least eight strikes on aid convoys and premises in Gaza since the war was sparked by Hamas' Oct. 7 terrorist attack on Israel.

"Israeli authorities did not issue advance warnings to any of the aid organizations before the strikes, which killed or injured at least 31 aid workers and those with them," the group said in a news release.

U.N. worker killed in Rafah

The United Nations said Monday, meanwhile, that one of its security staff was killed in an incident in the southern Gaza city of Rafah on Monday.

"The Secretary-General was deeply saddened to learn of the death of a United Nations Department of Safety and Security (DSS) staff member and injury to another DSS staffer when their UN vehicle was struck as they traveled to the European Hospital in Rafah," a spokesperson for U.N. Secretary-General Antonio Guterres said in a Monday statement.

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The U.N. did not specify what was believed to have hit the vehicle, but the IDF said in a statement sent to CBS News that the incident was under review.

"A report was received from the UNDSS organization that two of the organization's workers were injured today in the area of Rafah. An initial inquiry conducted indicates that the vehicle was hit in an area declared an active combat zone," the Israeli military said, adding that it had "not been made aware of the route of the vehicle."  

In:
• Hamas
• Israel
• United Nations
• Palestinians
• Gaza Strip
• Benjamin Neta​nyahu
• West Bank