The United States said it had "disabled" a Guinea-Bissau-flagged oil tanker in the Gulf of Oman that was attempting to carry Iranian crude, in what it described as the third such vessel struck this week, US Central Command said on June 11.

The action points to a sharp widening of US military operations beyond strikes on Iranian territory into the interdiction of commercial shipping, raising the prospect of disruption to tanker traffic in waters that adjoin the Strait of Hormuz and carry a significant share of the world's oil.

Central Command said its forces had acted against the tanker Jalveer as it sought to move oil from Iran through the Gulf of Oman, with a US Air Force aircraft firing two Hellfire missiles at the vessel's engine room after the crew refused to follow instructions, RIA Novosti reported on June 11.

The strike was the third against a merchant vessel during the week, according to the US military.

Washington framed the interdiction as enforcement of a blockade against Iran, signalling an intent to cut off Tehran's seaborne oil exports through physical action rather than sanctions alone.

Ahead of the announcement, India on June 11 summoned an American diplomat in New Delhi over an "attack" on a ship off the coast of Oman.