Japanese police on Thursday raided a machine tool maker for exporting equipment without government approval that can be used to make nuclear weapons, officials said.

Television footage showed officers raiding the headquarters of Horkos Corp. near the western city of Hiroshima, which was the site of the world's first atomic bombing on August 6, 1945.

Police were suspicious about the company's exports of equipment which is normally used to make auto parts but can be converted to produce centrifuge parts for uranium enrichment, a spokesman said.

Exports of such sensitive equipment normally require prior approval by the government.

The police spokesman declined to provide further details.

But public broadcaster NHK and Jiji Press, citing unnamed sources, said that the firm was suspected of exporting the machinery to South Korea from which it was sent to a third country.

Officials at Horkos could not be reached for a comment.

Authorities have in recent years cracked down on a number of Japanese firms over suspicious exports.

Four executives of precision equipment maker Mitutoyo were arrested in 2006 for illegally exporting nuclear equipment that was eventually found in Libya.