WASHINGTON (AP) — The U.S. on Thursday imposed sanctions on a group of individuals, firms and vessels connected to an oil smuggling outfit said to benefit the Lebanese militant group Hezbollah and Iran's Revolutionary Guard.

More than a dozen companies, six individuals and 11 vessels flagged from around the world — from Djibouti to Panama — are included in the sanctions package, for allegedly participating in a scheme that included blending and exporting sanctioned Iranian oil.

Treasury's Office of Foreign Assets Control said Viktor Artemov, Edman Nafrieh, Rouzbeh Zahedi, Mohamed El Zein and others used dozens of companies to conduct illicit activities.

The move comes after the State Department in September designated two Chinese companies, and Treasury penalized a network of companies based in Hong Kong, Iran, India and the United Arab Emirates for playing a critical role in shipping sanctioned Iranian oil.

The sanctions deny parties access to any property or financial assets held in the U.S.

"The individuals running this illicit network use a web of shell companies and fraudulent tactics including document falsification to obfuscate the origins of Iranian oil, sell it on the international market and evade sanctions," said Brain Nelson, Treasury's undersecretary for terrorism and financial intelligence.

Nelson said vendors and buyers "should be vigilant" about Hezbollah and the Iranian regime's attempts to generate revenue from oil smuggling.

The U.S. has ramped up sanctions against Iran and individuals and firms that do business with the country — especially after the September death of 22-year-old Mahsa Amini, who died in the custody of Iran's morality police.

She was detained because she didn't properly cover her hair with the mandatory Islamic headscarf, known as the hijab. Amini collapsed at a police station and died three days later.

Her death set off protests in dozens of cities across the country, and the government responded with a fierce crackdown, blaming the protests on foreign interference.