The U.S. Treasury Department sanctioned two crypto exchanges it says helped Iran move money outside the traditional banking system, widening Washington's campaign against digital asset networks allegedly funding the Islamic Revolutionary Guard Corps (IRGC).

The Treasury’s Office of Foreign Assets Control (OFAC) targeted Shelbit Exchange and Iran-based Aban Tether, according to a Friday press release. The agency also sanctioned Siavash Kayvanpour and several companies tied to him in Georgia, Poland and the United Arab Emirates. While the exchange doesn’t appear to be connected to stablecoin issuer Tether, CoinDesk has reached out to Tether to confirm if the exchange is unrelated to the firm.

IRGC-linked wallets sent more than $1 million in crypto to Shelbit addresses while more than $2 million flowed from Shelbit addresses to IRGC wallets, the Treasury said. Wallets belonging to or controlled by Kayvanpour also sent over $2 million to Nobitex, Iran's largest crypto exchange, according to the Treasury.

Aban Tether has processed millions of dollars in transactions involving sanctioned Iranian exchanges, including Nobitex, Wallex, Bitpin and Ramzinex, the press release added.

Additionally, the OFAC also sanctioned a network of foreign exchange houses, shell companies and individuals on Friday that it said helped Iran's shadow banking system move hundreds of millions of dollars, including funds tied to overseas oil sales.

“The Iranian regime’s reliance on digital assets and shadow banking networks is further evidence that Economic Fury is working,” Treasury Secretary Scott Bessent said in a statement. “Whether in dollars, rials, or crypto, Treasury will hunt down and dismantle the illicit financial networks that keep the regime afloat.”

The designations came as the U.S.-Iran war has raised the stakes of Washington's push to cut Tehran off from foreign currency and global financial markets. Cryptocurrencies may offer sanctioned entities another route to move funds when banks cut them off, but blockchain transactions can also leave a public trail that investigators and analytics firms can follow.

Friday's action is the latest in a string of U.S. measures against Iran's crypto finance network.

In January, the Treasury sanctioned Zedcex and Zedxion, the first crypto exchanges targeted under its Iran-specific financial sanctions. In June, the Treasury blacklisted Nobitex and several other Iranian crypto exchanges as part of its campaign against Tehran.

Last month, the U.S. sanctioned four crypto wallets linked to Iran's central bank, after which Tether, issuer of the largest stablecoin $USDT $USDT$0.9992, froze about $131 million held in the wallets. It also sanctioned two Iranian maritime insurance entities over an alleged scheme that funneled funds to the IRGC.