A U.S.-flagged tanker heading for Bahrain was approached and threatened by Iranian gunboats in the Strait of Hormuz, a British maritime security firm says.

US officials say seizure of more tankers carrying Iranian oil is under consideration to pressure Tehran, but fears of retaliation and market disruption have so far kept Washington cautious.

Iranian gunboats unsuccessfully attempted to intercept a US oil tanker in the Strait of Hormuz on Tuesday before a US Navy vessel intervened, reports say.

The United States has imposed sanctions on a fleet of nine ships accused of transporting hundreds of millions of dollars in forbidden Iranian oil to foreign markets.

Indian authorities have arrested and sanctioned three tankers linked to Iran in a crackdown on fuel smuggling. The Indian Coast Guard said that it had “busted an international oil-smuggling racket in a meticulously coordinated sea–air operation”. The three vessels were held about 100 miles west of Mumbai.

Iranian Shahed-139 drone shot down by F-35 jet over Arabian Sea • In separate incident, six Iranian gunboats approach US-flagged oil tanker in Strait of Hormuz