The U.S. Treasury Department imposed sanctions on a senior Egyptian Muslim Brotherhood official, three other individuals, and three entities accused of moving money to Hamas through an international web of charities, businesses, and informal banking networks.

The July 23 action centers on Mahmoud al-Abyari, a United Kingdom-based senior leader of the Egyptian Muslim Brotherhood and secretary-general of the Muslim Brotherhood General Secretariat. The Treasury Department said al-Abyari helped raise funds for institutions already under U.S. sanctions over their alleged ties to Hamas and worked with Muslim Brotherhood affiliates to provide the group with financial assistance.

The sanctions, issued by the Treasury Department’s Office of Foreign Assets Control, target what U.S. officials described as a layered financing system designed to obscure the origins and destination of the money. According to the department, charitable organizations, commercial companies, and underground banking services were used to collect, transfer, and disguise funds intended for Hamas’s military wing.

Two of the sanctioned entities—Indonesia-based Tujah Bulah Global, also known as Seven Spikes Global, and the Gaza-based Madad Palestine Charitable Society—were described by the department as Hamas fundraising fronts. Treasury officials alleged that donations collected by Madad Palestine ostensibly to help civilians were knowingly diverted to military activities.

The action also targeted Turkey-based El-Kahira for General Trading, which the Treasury Department accused of transferring hundreds of thousands of dollars for Hamas. The company’s owner and two shareholders were among the individuals designated. U.S. officials said El-Kahira operated an underground banking service involving conventional currency and cryptocurrency and also served organized-crime groups based in Sweden.

Under the sanctions, any property or financial interests belonging to the designated individuals and entities that are held in the United States—or controlled by U.S. persons—must be frozen and reported to OFAC. U.S. citizens and companies are generally barred from conducting transactions involving them. Businesses owned at least 50 percent, directly or indirectly, by sanctioned parties are likewise blocked.

Foreign financial institutions that knowingly facilitate significant transactions for those designated could also face secondary sanctions, including limits on their access to correspondent or payable-through accounts in the United States.

The Treasury Department said the action was coordinated with the FBI, the Drug Enforcement Administration, and U.S. Customs and Border Protection. It follows earlier measures announced in January and March aimed at disrupting financial facilitators, operatives, and organizations Washington accuses of sustaining Hamas’s international funding network.