The nonprofit group United Against Nuclear Iran (UANI) says the U.S. blockade of Iran has left dozens of fully loaded oil tankers stranded off Iran's coast, while other vessels are anchored outside the Persian Gulf near Sri Lanka.

In a shipping report released on October 5, the group said at least 50 tankers carrying Iranian oil remain stranded near Iran, a number roughly unchanged from two months ago. These vessels are mainly loaded with crude oil, but also carry petroleum products and liquefied petroleum gas.

UANI said other empty vessels are anchored at various locations across the Indo-Pacific because the U.S. blockade prevents them from returning to Iranian ports. Twenty vessels flying the Iranian flag are located off Sri Lanka, with another one off Oman.

The U.S. military has imposed a near-total blockade on Iran, seeking to increase economic pressure on Tehran and force it to submit. U.S. Treasury Secretary Bessent said in an interview with Axios that this week Iran will have "for the first time ever" no oil being transported at sea. U.S. military figures show that a total of 130 vessels have been forced to reroute.

UANI said that inside the Persian Gulf, at least 11 fully loaded tankers are anchored east of Kharg Island, Iran's main oil export terminal, with another five located farther south. The group said no tankers were seen loading oil at Kharg Island on Monday. According to preliminary ship tracking data compiled by media outlets, Iran did not load any crude oil onto tankers in September. This is the first time since the war broke out that Iran's monthly crude oil loadings have fallen to zero.