The U.S. Treasury Department announced sanctions against Hamas’s financial networks on Monday, as Washington continues to tighten the noose around the terror group’s international financiers.

The fifth round of U.S. sanctions against Hamas since the terror group’s Oct. 7 attacks, which Washington coordinated with the United Kingdom and Australia, includes designations against cryptocurrency exchanges used by Iran’s Islamic Revolutionary Guard Corps (IRGC) to transfer funds to Hamas and Palestinian Islamic Jihad.

“Hamas has sought to leverage a variety of financial transfer mechanisms, including the exploitation of cryptocurrency, to channel funds to support the group’s terrorist activities,” said Brian Nelson, under secretary of the treasury for terrorism and financial intelligence. “Treasury, in close coordination with our allies and partners, will continue to leverage our authorities to target Hamas, its financiers and its international financial infrastructure.”

“Since at least 2020, Hamas has also used cryptocurrency to transfer some funding in support of operational costs in the West Bank as a means of mitigating the risks of physically moving cash, circumventing border crossings and evading monitoring by authorities,” the statement added.

In a separate announcement on Monday, the department said that it is sanctioning an Iraqi airline and three leaders of the Iraq-based Kata’ib Hezbollah, one of Iran’s main proxy groups in the country and a designated terrorist group since 2009.

According to the Treasury Department, the IRGC has used the private Iraqi budget airline Fly Baghdad to shuttle weapons, cash and men between Iran and its proxy forces in Iraq, Syria and Lebanon, including in support of Hezbollah’s ongoing attacks against Israel.

“In October 2023, following Hamas’s horrific terrorist attack on Israeli civilians, Fly Baghdad was involved in the transfer of hundreds of Iraqi fighters, including fighters affiliated with U.S.-designated terrorist organization and Iranian proxy militia Asa’ib Ahl al-Haq, in support of the Iranian proxies’ attacks on Israel,” per the statement.

Since Hamas’s Oct. 7 terrorist attacks, Iranian proxies have stepped up their efforts to strike U.S. forces and interests throughout the region. 

The Yemen-based Houthi militant group, which the Biden administration will re-designate as a terrorist group in February, claimed on Monday that it successfully attacked the U.S.-flagged container ship Ocean Jazz, which has transported U.S. military cargo.

U.S. Naval Forces Central Command, which oversees U.S. naval operations in the Middle East, issued a statement denying that the Houthis had carried out the attack. Ocean Jazz transited the Red Sea safely, it said. 

As of Thursday, Iranian-backed forces have carried out some 140 attacks on U.S. service members in Iraq and Syria since Oct. 7, with almost 70 wounded, The New York Times reported.

On Sunday, Central Command stated that after a 10-day search, it was declaring two U.S. Navy SEALs deceased after an incident during an attempt to board and inspect a small boat that the United States said was “carrying Iranian advanced conventional weapons.” 

One of the SEALs reportedly fell into the water during the boarding operation, with the second diving after him, in accordance with protocol.