Hiroshima, Nagasaki protest nuclear weapons testing

The mayors of Hiroshima and Nagasaki , the two Japanese cities devastated by the world's only atomic bomb attacks, on Friday urged the United States and Britain to halt nuclear tests, saying they threaten the Nuclear Nonproliferation Treaty. British and American government scientists performed an underground nuclear experiment, short of a nuclear blast, at a test site in Nevada on Tuesday, the U.S. National Nuclear Security Administration said.

The experiment involved detonating high explosives around radioactive material in a vault about 300 meters (1,000 feet) below ground at a remote part of the desert testing range about 135 kilometers (85 miles) northwest of Las Vegas. In a statement, Hiroshima Mayor Tadatoshi Akiba said he sent letters to both U.S. President George W. Bush and British Prime Minister Tony Blair to protest the test. Nagasaki Mayor Itcho Ito said in a separate release that he sent similar letters of protest to the U.S. and British ambassadors to Japan .

"You have brought the Nuclear Nonproliferation Treaty, the international agreement regarding nuclear weapons, to the brink of collapse, and we fear, are provoking a new round of proliferation," Akiba wrote. He urged the United States to halt all nuclear testing, including subcritical testing.

The world's first atomic bomb was dropped on Hiroshima in the closing days of World War II by a U.S. plane. The blast, on Aug. 6, 1945 , killed or wounded 160,000 people. Three days later, another U.S. atomic bomb leveled Nagasaki , killing about 70,000 people. On Aug. 15, 1945 , Japan 's surrender ended the war. This week's testing was the 22nd subcritical test conducted at the site since 1997.

The U.S. 's repeated nuclear tests "may give a pretext to develop nuclear weapons of other countries," Ito said in a letter. Separately, representatives of the Japan Confederation of A-and-H Bomb Sufferers" Organizations handed a letter of protest to a staff member at the U.S. Embassy in Tokyo, said confederation spokeswoman Michiko Kakezuka, reports the AP.

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