The Trump administration on Friday unveiled sanctions against three individuals allegedly related to the Islamist militant group Hamas and against two charities based in France while also announcing six arrests – actions that the government called an “extraordinary counter-terrorism work” to expose “a sophisticated, multi‑year financing architecture”.

Investigators alleged that the network moved more than $2m to Hamas “through deceptive charitable fronts and cryptocurrency channels”.

The United States treasury department announced that all property in the US of those sanctioned is “blocked and must be reported” to the Office of Foreign Assets Control (OFAC) – and that entities owned by those individuals are also blocked.

“Terrorist organizations like Hamas rely on sophisticated financial facilitators and fraudulent schemes designed to exploit the public to sustain their operations,” US treasury secretary Scott Bessent said in a statement. “Treasury will continue to identify, isolate, and impose consequences on those who provide Hamas with the financial lifelines it needs to survive.”

Those sanctioned are Saleem Alzaq, accused of being part of the Hamas military wing and based in Gaza, as well as Faouzi Barika and Amel Oualid, both residents of France who run charities “ostensibly to raise money for humanitarian purposes to aid Gazan civilians”, according to the treasury.

The charities sanctioned are Association Baraka and Ensemble C Mieux. The three of them allegedly collected more than $2m for Hamas during a six-year period beginning in 2020. And treasury officials said $1.5m was raised after Hamas’ deadly 7 October 2023 attack on Israel, which responded by launching war in Gaza.

Meanwhile, the US justice department on Friday announced the unsealing of an indictment charging one man and the arrests of another three for their alleged “involvement in paying, soliciting and collecting funds for Hamas”. As part of that same plot, three other associates were arrested in France.

The FBI said those men were engaging in a conspiracy to “funnel money to Hamas and fuel violent attacks”.

Alzaq, 45, was the man indicted on charges of conspiring to provide material support to Hamas, among other counts. He allegedly “operated an international Hamas fundraising network that collects donations from individuals around the world, including … in the United States”, US attorney Jamie McDonald of New York’s southern district said in a statement.

The US justice department also described Alzaq as a Hamas member in the Gaza Strip and a battalion deputy in the group’s armed wing. Justice department officials accused him of serving in “a Hamas propaganda office” as a photographer who “posted propaganda” of the organization on social media.

Two of the three men arrested in the US were identified as Omar Adhami and Abdel Adhami, residents of the New Orleans suburb of Covington, Louisiana. The third was identified as Raed Yousef of the Tampa suburb of Lutz, Florida.

A statement attributed to the US attorney for Louisiana’s eastern district, David Courcelle, alleged that the Adhamis provided Alzaq with “resources intended to fund Hamas’ relentless reign of terror”.

The Adhamis and Yousef were accused of contributing tens of thousands of dollars to Hamas and could face up to 80 years in prison if convicted as charged. Some of the charges that they face include conspiracy to provide material to “a designated foreign terrorist organization” and conspiracy to commit money laundering.

A statement from the Trump administration’s attorney general Todd Blanche said “anyone who finances or assists” terrorist groups should expect to face federal prosecution.

A separate statement from the Trump administration’s FBI director Kash Patel said the agency would “never forget the horrific attack on Israel by Hamas” on 7 October 2023 – and that it would “never stop … efforts to cut off funding to Hamas terrorists”.