The US military said it is investigating the cause of the accident, which Garcia said happened at about 10:15pm (2015 GMT) on Monday.

"Overall damage to the USS Newport News is being evaluated. The propulsion plant was unaffected by this collision," Garcia said.

In Tokyo, the Japanese foreign ministry said the submarine's bow collided with the stern of the oil tanker.

"Apparently, there were no injuries on the submarine or the tanker," the ministry said in a statement, citing US government information.

The tanker was operated by Kawasaki Kisen Kaisha, or K Line, according to a spokesman for Showa Shell Sekiyu, which contracted the vessel.

"We have learned there were no injuries and or oil leak," he told AFP.

Japan's Transport Minister Tetsuzo Fuyushiba also told reporters there appeared to have been no oil leakage from the tanker.

"The ship was able to navigate on its own, and apparently no one was injured," he said.

After the accident, the tanker was headed to the nearest port in the United Arab Emirates, the Japanese foreign ministry said, adding that Japan had asked the United States to investigate the cause of the incident.

The Newport News, a 110-meter (360-foot) long, Los Angeles-class fast attack submarine, carries a crew of 127 and is based in Norfolk, Virginia.

The submarine is part of the carrier group supporting the USS Dwight D. Eisenhower, an aircraft carrier. The group is deployed in the Gulf region.

In a statement from the headquarters of the US Fifth Fleet in Manama, officials said the incident "is currently under investigation."

The USS Newport News, it dded, is on a "regularly scheduled deployment" conducting maritime security operations, which help "deny international terrorists use of maritime environment as a venue for attack or to transport personnel, weapons or other material," the statement read.

On February 9, 2001 the nuclear-powered US submarine Greenville sank the Japanese fisheries training ship Ehime Maru during a rapid ascent off the coast of Hawaii, killing nine people on board, including four teenage students.

Commander Scott Waddle, who commanded the Grenville and was hosting civilian guests at the time of the accident, accepted responsibility for the fiasco and was reprimanded, then allowed to retire from the navy.

earlier related report
Russian naval expert claims U.S. sub captain to blame for crash
Moscow (RIA Novosti) (SPX) Jan 9 - The captain of a United States nuclear submarine was probably to blame for a collision with a Japanese tanker in the Arabian Sea, a Russian naval expert said Tuesday.

The USS Newport News collided Monday night with Japanese oil tanker Mogamigawa near the Strait of Hormuz. The vessels suffered minor damage but no injuries, fuel spills or radiation have been reported.

"The incident involving the American submarine and the Japanese vessel in the Arabian Sea was due to intensive traffic of vessels in this region, which demands a high level of caution from captains of navy vessels, in particular from captains of nuclear submarines," the expert said. "Most likely, the captain of the American vessel inadequately assessed the underwater and surface situation while the submarine was surfacing."

The collision is not the first between a U.S. submarine and a Japanese vessel. In February 2001, U.S. nuclear submarine Greenville ran into and sunk a Japanese fishing vessel near Hawaii, killing all nine people on board the Japanese boat.

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