KYODO Sasebo Nagasaki Pref.

The municipal government of Sasebo, Nagasaki Prefecture, will ask the central government to promptly dispose of radioactive waste being stored by the U.S. Navy at the Sasebo Naval Base, city officials said Friday.

The waste is from the U.S. military's relief efforts following the March 11 disaster.

The materials include cleaning cloth and other items used to decontaminate aircraft, the officials said. They contain low levels of radioactive substances, most likely from the Fukushima No. 1 nuclear plant.

Sasebo officials were unaware of the materials until they received an inquiry from the media Thursday. They approached the Foreign Ministry, which later confirmed with the U.S. military that radioactive waste is being kept at the base.

The ministry told the city later Thursday that while the central government will handle the disposal correctly, Tokyo and Washington are still discussing details of how to do so, according to the Sasebo officials.

The city believes there are no safety concerns because monitors at six locations near the base have found no abnormalities so far.