Foreign Minister Makiko Tanaka admitted Tuesday she was careless in revealing a top secret matter regarding the U.S. just hours after the Sept. 11 terrorist attacks on the World Trade Center and the Pentagon.

Early Sept. 12, Tanaka told reporters that U.S. State Department officials had evacuated and went on to reveal the location where they had taken shelter -- a facility that could have become the target of another attack.

"It was an emergency situation and various information was going around . . . but I must say (the remark) was careless," Tanaka told reporters.

Vice Foreign Minister Yoshiji Nogami said Monday that the information was "of course top secret" at the time. He refused to say how the U.S. reacted to Tanaka's remark.

Tanaka claimed she had not been told to keep the information confidential and has not received a protest from the U.S. government.

During the incident, Tanaka told reporters that staff in the State Department, which is in Washington close to the Pentagon, had evacuated to a training institute in Arlington, Va. She also said the department's ad hoc headquarters was being headed by Deputy Secretary of State Richard Armitage, citing information from the State Department.

Following Tanaka's remarks in front of TV cameras, senior Foreign Ministry bureaucrats decided not to report secret information to her, ministry sources said.

Shunji Yanai, the Japanese ambassador to the U.S., said releasing such information could harm Japanese-U.S. ties. Prime Minister Junichiro Koizumi and Chief Cabinet Secretary Yasuo Fukuda were both alarmed by Tanaka's disclosure, the sources said earlier.

Meanwhile, the Foreign Ministry announced later Tuesday that Tsukasa Uemura -- a secretary to Tanaka who has been on leave since reportedly collapsing from exhaustion two weeks into his job -- has been relieved of his duties and assigned to serve as senior assistant at both the First North America Division and Policy Coordination Division.

Uemura worked as director of the First Middle East Division at the ministry's Middle Eastern and African Affairs Bureau until his appointment April 26 as secretary to Tanaka.