The US Department of the Treasury’s Office of Foreign Assets Control (OFAC) has identified three individuals and one charity as having significant financial ties to the Palestinian terrorist group Hamas.

In a statement released on Monday, the one-year anniversary of Hamas’s Oct. 7 massacre across southern Israel, OFAC announced new sanctions against the entities spotlighted by its investigation and noted they play integral roles in funding Hamas’s terrorism ventures under the guise of “charitable work.” The department said that the investigation was part of its efforts to surface abuses by self-described “charity organizations” really working to financially support terrorist groups.

“As we mark one year since Hamas’s brutal terrorist attack, Treasury will continue relentlessly degrading the ability of Hamas and other destabilizing Iranian proxies to finance their operations and carry out additional violent acts,” US Secretary of the Treasury Janet Yellen said in a statement. “The Treasury Department will use all available tools at our disposal to hold Hamas and its enablers accountable, including those who seek to exploit the situation to secure additional sources of revenue.”