Hamas has been accused of putting a bounty on the heads of American aid workers in Gaza, and the Palestinians who support them.
The Gaza Humanitarian Foundation (GHF) said it had received credible reports that the terror group was offering cash for the killing of contractors distributing food.
In a statement late on Saturday, the GHF said Hamas had also 鈥減re-positioned鈥 operatives near its distribution centres in a bid to disrupt the flow of aid.
It follows the massacre of 12 Palestinian GHF staff earlier this month.
GHF began operations in Gaza at the end of May, following a nearly three-month Israeli blockade on humanitarian aid entering Gaza.
It has created a handful of purpose-built distribution centres where a family member can collect aid for their loved-ones.
Supported by Israel and the US, the model, which is intended to prevent aid being seized by Hamas, has been criticised by much of the rest of the international community, and NGOs, as being inhumane and not fit for purpose.
Numerous mass shootings of Gazans have taken place near the GHF centres, with eyewitnesses blaming Israeli troops, who provide an outer layer of security. The IDF (Israel Defense Forces) deny this and says they have fired only warning shots.
The IDF last week launched an internal probe into the claims.
Israel, along with the GHF, has repeatedly claimed that Hamas has tried to disrupt the collection of aid by intimidating the population and firing on them near aid sites.
鈥淭he targets of Hamas鈥檚 brutality are heroes who are simply trying to feed the people of Gaza in the middle of a war,鈥 GHF said.
鈥淥ur US security personnel, some of America鈥檚 most elite and decorated veterans, are on the ground to protect people.
鈥淎nd our local staff, who keep these operations running, have already paid the ultimate price: twelve murdered, others tortured, and now more threats emerging by the day.鈥
One Gazan source told The Telegraph they had seen no written material, on social media or elsewhere, to support the claim that Hamas was offering cash rewards to kill GHF staff and that promising bounties was not part of the terror group鈥檚 normal playbook.
It follows the approval by the US State Department of $30 million (拢22 million) to prop up the controversial new aid model.
Looting of aid trucks
Separately, Benjamin Netanyahu and Israel Katz, the defence minister, have reportedly tasked the IDF with coming up with a new way of getting aid trucks into Gaza, amid increased looting.
Hamas has been implicated in the looting. Armed family gangs, known as clans, have also reportedly played a role, while other reports suggest an increasingly hungry population has taken to plundering trucks on occasion.
At least 81 Gazans were killed and more than 400 injured in Israeli strikes across the enclave in the 24 hours up to midday on Saturday, according to the Strip鈥檚 Hamas-run health authority.
Eleven people, including children, were reportedly killed in a single strike on a tented area for displaced children, according to reports.
Meanwhile, tensions continue to escalate in the West Bank.
A political row has broken out after the IDF soldiers used live ammunition to contain allegedly violent Israeli settlers.
The troops鈥 actions were criticised by the ultra-nationalist finance minister Bezalel Smotrich, who comes from the West Bank settler community, as 鈥渃rossing a red line鈥.
Other leading politicians have accused him, and his cabinet colleague, the security minister Itamar Ben-Gvir, of fuelling settler violence in the first place.