Washington imposed sanctions on 29 vessels, their management companies and related firms on Thursday as it targeted Tehran's alleged "shadow fleet" that exports Iranian oil and petroleum products.

U.S. Treasury says the targeted vessels and firms have shipped hundreds of millions dollars worth of products using deceptive shipping methods.

The shadow fleet is a term used to describe ships that are carrying oil under sanctions. The ships are usually old, the ownership is opaque and they sail without top-tier insurance coverage needed to meet international standards.

Treasury will continue to "deprive the regime the petroleum revenues it uses to finance its military and weapon programs", John Hurley, Department's Undersecretary for terrorism and Financial Intelligence, stated in a press release.

The Iranian mission in the United Nations did not respond immediately to a request for comment.

The U.S. claims to impose sanctions on Iran because of its nuclear program and support for militant proxies in the Middle East. Iran claims its nuclear work has civil purposes.

The tensions between Tehran, Washington and Israel have increased after five rounds of indirect negotiations on nuclear issues. This culminated in a 12-day air war in June where Israel and the U.S. attacked Iranian nuclear sites.

The action on Thursday also targets Egyptian businessman Hatem Elsaid Farid Ibrahim Sakr. His?companies' are linked to seven of the vessels mentioned, as well as several shipping companies.

This month, the U.S. took additional action against a Venezuelan oil tanker that was originally sanctioned for carrying Iranian oil by Washington.

On December 10, the U.S. seized a tanker named Skipper off the coast of Venezuela, which was carrying crude oil from that South American nation. This move heightened tensions between Washington and Caracas.

In 2022, the administration of former president Joe Biden imposed sanction on the tanker for what they say was its involvement in the trading of Iranian oil when it was known as the Adisa.

(source: Reuters)