TOKYO (AP) _ A strong earthquake in northern Japan on Wednesday may have led the Tokyo government to suspect that North Korea had conducted a second nuclear test.
In Washington, White House spokesman Blair Jones said U.S. officials had not detected any evidence of additional North Korea testing.
``Japanese officials are now saying that this occurrence may be related to an earthquake in northern Japan,'' Jones said.
The earthquake came at a time when the Japanese government and other countries in Asia were jittery about reports that North Korea planned a second nuclear test.
``We have very real concerns that they may conduct another nuclear test and that they may do so very soon,'' Australian Foreign Minister Alexander Downer told reporters on Wednesday, a day after he met with North Korea's ambassador to his country.
The scare began when Japanese media reported the government had detected tremors in North Korea, leading it to suspect Pyongyang had conducted a second nuclear test. Around the same time, the Japanese meteorological agency said a strong earthquake shook northern Japan.
Then Japanese Prime Minister Shinzo Abe said he had no information to confirm North Korea had conducted a second nuclear test.
``I have had not received information about any indications ... that a test has take place,'' Abe said at a parliamentary budget meeting.
U.S. and South Korean monitors said they detected no new seismic activity Wednesday in North Korea.