TOKYO (Reuters) - The U.S. Navy said it had replaced the captain of a nuclear-powered aircraft carrier scheduled for a controversial berth in Japan after blaming him for a fire on board on the warship.

USS George Washington (CVN73) is shown in the Arabian Sea, November 19, 1997. REUTERS/Files

The United States has been trying to allay fears over the planned stationing of the George Washington in Japan, the only country to have suffered nuclear attacks.

Doubts about the ship’s safety were renewed when a fire broke out on board in May, and the plan has sparked two demonstrations in recent weeks.

U.S. Naval Air Forces said in a statement it had fired commanding officer David C. Dykhoff and another officer over the incident and installed Captain J.R. Haley as the ship’s new commander.

A U.S. investigation determined that the likely cause of the fire, which blazed for 12 hours and seriously injured one sailor, was unauthorized smoking that ignited oil stored inappropriately, the statement said.

Rear Admiral James Kelly, the head of the U.S. Navy in Japan, and James Zumwalt, a senior U.S. Embassy official in Tokyo visited Japanese foreign ministry officials to explain the results of the investigation, the ministry said in a statement.

Japanese officials told their U.S. counterparts they were satisfied with the investigation, but wanted U.S. forces to continue to make efforts to prevent a recurrence.

Tokyo is also satisfied that the ship is safe, the foreign ministry said.

The George Washington is currently undergoing $70 million dollars of repairs in San Diego, which has delayed its arrival in Japan by several weeks.

It is now scheduled to depart the United States on August 21 and arrive in Yokosuka, 45 km (28 miles) southwest of the heavily populated capital, in late September, the statement said.

Many Japanese are sensitive about the use of nuclear power by military forces. The Japanese cities of Hiroshima and Nagasaki came under nuclear attack from the United States at the end of World War Two in August 1945.