Defense Minister Yasukazu Hamada decided Tuesday to voluntarily return part of his salary for November over a controversial essay on Japan's role in World War II written by then air force chief Gen. Toshio Tamogami, who has since been sacked, ministry officials said.

Because there are no rules on reprimanding parliamentarians in the Defense Ministry, Hamada, a legislator, decided to take the action to punish himself for failing to supervise Tamogami, who authored an essay containing views on the war at variance with the position of successive Japanese governments. The essay was made public on Friday.

Senior Vice Defense Minister Seigo Kitamura and parliamentary defense secretaries Nobuo Kishi and Ryota Takeda, also parliamentarians, followed Hamada's example.

Meanwhile, the ministry issued reprimands to Vice Defense Minister Kohei Masuda and two other senior bureaucrats over the affair, the officials said.

Hamada is to return to the public coffers some 169,000 yen, Kitamura about 63,000 yen, and Kishi and Takeda around 40,000 yen. Masuda incurred a 10-percent cut in salary for November, the officials said, or about 121,000 yen.

The moves came after Prime Minister Taro Aso told Hamada earlier Tuesday to ensure there is no repeat of the kind of controversy caused by the recent release of Tamogami's essay.

While Cabinet members regard the dismissal of Tamogami as the ASDF chief of staff as an appropriate response, the main opposition Democratic Party of Japan stepped up its attacks on the Aso government.

In a meeting Tuesday morning, Aso told Hamada to punish relevant personnel in the Defense Ministry and the Self-Defense Forces as well as to tighten civilian control over the SDF, especially with regard to public expressions of political opinions by ranking officers, Hamada told a press conference.

The move came after the government allowed Tamogami, 60, to leave the ministry effective Monday after removing him from the post of the ASDF's chief of staff on Friday.

Tamogami is eligible to receive a retirement allowance as the ministry stopped short of dismissing him.

Hamada indicated he was able to remove Tamogami from the post of ASDF chief, but that it would have been inappropriate to fire him from the ministry because of his right of freedom of speech.

Tamogami has had no contact with Hamada since his dismissal as the ASDF chief Friday evening, and there were no indications that Tamogami had tendered his resignation, the defense minister said.

Tamogami's essay denying Japanese military aggression in Asia before and during World War II was released Friday as winner of a 3 million yen top prize in a competition organized by hotel and condominium developer Apa Group.

Ministry sources said more than 50 other SDF officers wrote essays for the competition, but details about the contents of their essays are not yet known.

Meanwhile, the DPJ decided Tuesday to seek to have Tamogami summoned to the opposition-dominated House of Councillors Committee on Foreign Affairs and Defense to give unsworn testimony on the controversy, DPJ Secretary General Yukio Hatoyama said.