JERUSALEM - Individual members of Israel’s security forces are tipping off far-right activists and settlers to the location of aid trucks delivering vital supplies to Gaza, enabling the groups to block and vandalise the convoys, according to multiple sources.

Settlers intercepting the vital humanitarian supplies to the strip are receiving information about the location of the aid trucks from members of the Israeli police and military, a spokesperson from the main Israeli activist group behind the blockades told the Guardian.

The claim of collusion by members of the security forces is supported by messages from internal internet chat groups reviewed by the Guardian as well as accounts from a number of witnesses and human rights activists.

Those blocking the vehicles say the aid they carry is being diverted by Hamas instead of being delivered to civilians in need a claim relief agencies reject.

Rachel Touitou, a spokesperson for the Israeli group Tzav 9, said the group had been blocking trucks as they made their way through Israel since January, on the grounds that the aid they carried was “hijacked” by Hamas once it reached Gaza.

“When a policeman or soldier’s mission is supposed to protect Israelis and instead he is sent to protect humanitarian aid convoys – knowing it will end up in the hands of Hamas – we cannot blame them or civilians who notice the trucks passing by their towns for providing intel to groups trying to block that aid. Yes, some of our intel comes from individual members of Israeli forces,” Touitou added.

Videos last week showed aid convoys blocked and vandalised by Israeli settlers at the Tarqumiya checkpoint, west of Hebron in the Israeli-occupied West Bank. The incident, in which activists threw boxes of supplies to the ground, sparked outrage, with the White House condemning the attack as “completely and utterly unacceptable behaviour”.

Photographs from the scene showed piles of damaged aid packages and trails of rice and flour across the road. Photographs later circulated on social media showing the trucks on fire.

Touitou said: “It was not Tzav 9 that burned the trucks … this was not our action,” adding that other groups were responsible for the arson attack.

The settlers say they are blocking the aid trucks in order to stop supplies reaching Hamas and accuse the Israeli government of giving “gifts” to the Islamist group.

“Our purpose is to highlight that feeding your enemy, in this specific case Hamas, especially during a time of war, is immoral,” said Touitou. “Israel has been delivering this humanitarian aid without expecting anything in return. And 80% of the population agrees with our stance. Hamas is reselling this aid to civilians, which is meant to be distributed for free. We will continue to block this humanitarian aid until they can prove that it is reaching the civilians.”

Palestinian lorry drivers delivering aid to Gaza have described to the Guardian “barbaric” scenes” after their vehicles came under attack, claiming that Israeli soldiers escorting the convoy did nothing to intervene.

Yazid al-Zoubi, 26, a Palestinian lorry driver who was attacked by the protesters last week at Tarqumiya checkpoint, said: “There is full cooperation between the settlers and the army. We are shocked and surprised that the army did not provide us with any kind of protection. Even though they were present and watching what was happening. The army was at the service of the settlers.”

Two soldiers from Israel’s Home Front Command refused an order to evacuate protesters who blocked aid trucks in the Makhash area last week, according to the IDF. One of them was sentenced to 20 days in prison, Israel’s national broadcaster, Kan, reported.

An IDF spokesperson said: “A female reserve fighter refused to carry out a task to maintain order in an area that was defined as a closed military area and as a result she was brought to disciplinary proceedings accordingly. The fighter was convicted of the crime of refusing an order. This is an incident that is not consistent with what is expected of IDF soldiers while fulfilling their mission.”

Footage of the incident obtained by the Guardian appears to show Israeli soldiers escorting the convoy, taking no action against the settlers.

The same settlers and far-right activists often notify their members in advance about the times and locations that aid trucks are heading towards Gaza, citing that they receive this information from the Israeli police and military.

In one such message seen by the Guardian, far-right activists alerted members that they would “receive preliminary information about the planning of moving trucks, from border crossings’ soldiers and police”.

In another message in a settler WhatsApp group, a member wrote on Sunday: “I received information from an officer in the IDF that they bring the trucks in front of Ofra [a settlement] into Bitin [a Palestinian village].”

“When an emergency call about a convoy of trucks is received,” the first message says, “the group opens for discussions, and when this happens please only send messages related to the blockade, such as locations, photos, information and hitchhiking.”

Touitou said that most of the information they received came from civilians. “Often it is the same Israelis who report aid convoys passing by. After eight months into the war, Israelis are frustrated with how aid is being managed in Gaza. If it is soldiers, policemen, or civilians like me, you cannot expect us to accept that aid will end up in the hands of Hamas.”

Sapir Sluzker Amran, an Israeli human rights lawyer who last week visited the Tarqumiya checkpoint to document the settlers’ actions and to prevent the aid from being looted, said she was beaten and slapped by a settler and that Israeli security forces did nothing to stop the assault.

“The settlers had guns and knives,” Sapir said. “I asked the IDF soldiers to stop them as what they were doing was illegal, but they asked me to leave. At some point, as I was trying to prevent an aid truck from being vandalised, a settler slapped me very hard and went away. I filmed him and took photos of him. I went to the police and asked them that I needed their help as I wanted to press charge against the man. Again, they asked me to leave. The Israeli forces let the man who attacked me free to vandalise the trucks.”

Alleged collaboration between the army and the settlers has been denounced for years by Palestinians and human rights organisations. In 2016, the IDF corporal Elad Sela, a resident of the Bat Ayin settlement who served in the Etzion regional brigade, was sentenced to 45 months in jail for passing on classified information to extreme activists, allowing them to evade arrest and continue their activities.

In October 2022, Maj Gen Herzi Halevi, who lived in the West Bank settlement of Kfar HaOranim, was appointed as Israel’s military chief of staff, in a move that highlighted the army’s relationship with settlers.

The Israeli police and Cogat, an Israeli defence ministry agency, declined to comment on the allegations that members of the security forces were helping those blocking aid deliveries.

In a statement, Nir Dinar, the head of the IDF’s international press department, rejected the allegations as “a baseless claim that I am hearing for the first time”. Dinar said police were investigating incidents relating to the blocking and vandalisation of the convoys. “IDF is working to prevent these kind of events,” he added.

On Sunday, the far-right national security minister, Itamar Ben-Gvir, suggested the government itself should be stopping aid trucks to Gaza instead of leaving it to groups of activists.

“We are in a democratic country and I am in favour of freedom of protest. They are allowed to demonstrate,” he said in an interview with Army Radio. “I am against them attacking and burning trucks … It’s the cabinet that should be stopping the trucks.”