Iran has blacklisted 45 tankers over allegations that they violated rules for transiting the Strait of Hormuz. The Iran-established Persian Gulf Strait Authority announced the measure in a post on X on Sunday night, saying Tehran could also act against any vessel transporting goods through the listed tankers.

The authority said blacklisted vessels could face fines, detention and confiscation of their cargo. The list includes large crude-oil tankers, ships carrying liquefied natural gas and liquefied petroleum gas, and vessels transporting clean products.

The warning came days after the United States threatened what it called the toughest sanctions in history against Iran. Iran said its response to any new US threat would be devastating. Tehran had previously said shipowners must obtain its approval to use the Strait of Hormuz and pay for security and other services. Before the conflict, the waterway carried about 20 percent of global daily crude oil and LNG supplies, but traffic has fallen sharply during the ongoing conflict.