A nuclear-powered U.S. submarine and another U.S. vessel collided on Friday in the Strait of Hormuz but there was no damage to the atomic propulsion unit, the U.S. Navy said.
Around 40 percent of globally traded oil leaves the Gulf region through the Strait of Hormuz, a choke point at the southern end of the Gulf, flanked by the coastlines of Iran and Oman. Here are some facts about the Strait of Hormuz.
* WHERE IS THE STRAIT?
-- A narrow bend of water separating Oman and Iran connects the biggest Gulf oil producers, such as Saudi Arabia, with the Gulf of Oman and the Arabian Sea.
-- At its narrowest point, the Strait is only 34 miles across.
-- The Strait consists of 2-mile (3.2-km) wide navigable channels for inbound and outbound tanker traffic as well as a 2-mile-wide buffer zone.
* OIL SHIPMENTS:
-- Oil movements through the Strait account for roughly 40 percent of all seaborne oil traded in the world, according to the U.S. Energy Information Administration (EIA).
-- In July 2008, the International Energy Agency (IEA) estimated that more than 15 million barrels per day (bpd) of crude passed through the narrow channel on tankers.
-- Ninety percent of oil exported from Gulf producers is carried on oil tankers through the Strait.
-- The bulk of the oil exported through the Strait of Hormuz travels to Asia, the United States, and Western Europe. Some three-quarters of all Japan's oil needs pass through this Strait.
-- An additional 2 million barrels of oil products, including fuel oil, are exported through the passage daily, as well as liquefied natural gas (LNG).
-- Exports from the world's largest LNG exporter, Qatar, pass through the Strait en route to Asia and Europe, totaling 31 million tons a year.
-- The EIA predicts oil exports passing through the strait will double to between 30 million and 34 million bpd by 2020.
-- One of U.S. Central Command's key missions in the Gulf is to ensure the free flow of oil and energy supplies.
-- Between 1984 and 1987, a "Tanker War" took place between Iran and Iraq, where each nation fired on the other's oil tankers bound for their respective ports. Foreign-flagged vessels were caught in the crossfire.
-- Shipping in the Gulf dropped by 25 percent because of the exchange, forcing the intervention of the United States to secure the shipping lanes.
* STRATEGIC CORRIDOR:
-- Merchant ships carrying grains, iron ore, sugar, perishables and containers full of finished goods also pass through the strategic sea corridor en route to Gulf countries and major ports like Dubai.
-- Heavy amour and military supplies for the U.S. armed forces in Iraq and other Gulf countries pass through the channel aboard U.S. Navy-owned, U.S.-flagged and foreign-flagged ships.
Sources: International Energy Agency (IEA), U.S. Energy Information Administration (EIA), United Nations Conference on Trade and Development (UNCTAD), GlobalSecurity.org, U.S. Navy's Military Sealift Command, Clarkson shipping consultancy.
(Complied by Alex Lawler and David Cutler)