A senior Reconstruction Agency official has been suspended for 30 days after repeatedly posting derogatory messages on his Twitter account against citizens' groups and authorities in areas hit by the 2011 earthquake and tsunami.

Reconstruction minister Takumi Nemoto announced the disciplinary measure against Yasuhisa Mizuno, 45, on Friday, explaining that the messages were posted during work hours and undermined the public's trust in civil servants.

The government's decision to suspend him a week after the incident was revealed is apparently aimed at drawing a curtain over the matter as soon as possible to mitigate its impact on the Upper House election next month.

Mizuno was transferred to the Internal Affairs and Communications Ministry, attached to the minister's secretariat.

After attending a rally in March organized by a citizens' group that supports disaster victims, Mizuno wrote on Twitter that he "attended the rally only to be denounced by left-wing hecklers."

Mizuno also wrote derogatory messages about unidentified lawmakers, such as "My head was left spinning after hearing a certain minister tell lies incessantly," the Reconstruction Agency said, adding that it has established in-house regulations to prevent its officials from posting personal or inappropriate information on the Internet.