China has prohibited the export of dual-use items to 20 Japanese entities that it says supply Japan’s military, the commerce ministry announced on Tuesday.

The measure targets units of major Japanese industrial conglomerates such as Mitsubishi Heavy Industries’ shipbuilding and aero engines divisions, the ministry said, without specifying the controlled items.

The restrictions were aimed at curbing Japan’s “remilitarisation” and nuclear ambitions, it said, adding overseas organisations and individuals were also banned from transferring Chinese-origin dual-use items to the listed entities.

Firms could apply to sell to the listed entities under “special circumstances” that required them to export, the ministry said in a statement.

China has assured that entities operating “in good faith” have no reason to worry, and that the measures announced will not affect normal economic and trade exchanges between the two countries.

The commerce ministry also added another 20 Japanese entities, including Subaru Corp, Itochu Aviation and Mitsubishi Materials Corp to a watch list, saying it could not verify the end-users or end-uses of the entities’ dual-use items.

Subject to stricter scrutiny, companies exporting to these entities would have to apply for individual export licenses for dual-use items and provide a written commitment that the items would not contribute to enhancing Japan’s military capabilities.

None of the affected Japanese companies contacted by Reuters had an immediate comment on the trade measures. Market reaction in Tokyo was mixed, with Subaru shares falling 3.7% while Mitsubishi Materials shares rose 3% and Mitsubishi Heavy shares were down 3.5%.