Washington, May 29 : The United States sanctioned many companies, individuals and vessels as part of a sweeping new crackdown on Iran's oil and petrochemical trade, accusing them of helping facilitate transactions involving Iranian-origin products.

The US Department of State announced sanction on several companies linked to what it called Iran's "shadow oil economy", saying the measures are intended to cut off revenue used by Tehran to fund destabilising activities and support its military apparatus.

The action formed part of a broader sanctions package targeting traders, shipping companies and vessels allegedly involved in transporting Iranian petroleum and petrochemical products.

"Todayâ??s sanctions action also targets three companies trading Iranian petrochemical products and one of their principal executive officers," the State Department said. It added that such companies provide "valuable revenue for the Iranian regime".

The sanctions targeted companies based in Qatar, Singapore, Hong Kong, the United Arab Emirates and the Marshall Islands.

The State Department designated eight vessel management companies and identified eight vessels as blocked property. It alleged that the companies were involved in the purchase, acquisition, sale, transport or marketing of Iranian petroleum and petrochemical products.

According to the department, Iranian exports are moved through networks of shipping facilitators operating across multiple jurisdictions. It accused some vessels of engaging in "dark activity and other deceptive shipping practices" while transporting Iranian cargoes.

At the same time, the US Treasury Department sanctioned what it described as an oil sales network that facilitated the movement of tens of millions of barrels of Iranian oil. The State Department said the network directly funded the Islamic Revolutionary Guard Corps (IRGC), Iran's Armed Forces General Staff and other elements of Iran's military establishment.

/IANS