Intensifying political tensions have begun to affect a wider range of Japan-related businesses in China through an apparent ban on book publishing in Beijing that may spread to other areas, Japanese publishing sources said Wednesday.

The sources said several Chinese publishers in Beijing were notified by authorities Friday that they must halt the planned publication of books written by Japanese or protected by Japanese copyrights, and books related to Japan that are being written by Chinese authors.

The ban will also affect cultural exchange events, copyright trading with Japan and the promotion of Japan-related books in the country, they said.

However, further details — including whether all Chinese publishers are being banned and for how long — remain unclear.

"Some Chinese publishers say small private publishers are banned and others say state-run publishers are banned," said one Japanese publishing source who was told about the order by several Chinese publishers.

Tensions between Japan and China heightened last week after the Japanese government nationalized the Senkaku Islands, known in China as Diaoyu.

Anti-Japan protesters damaged plants run by Panasonic Corp. and dealerships run by Toyota Motor Corp., Nissan Motor Co. and Honda Motor Co., and stores run by Aeon Co. and Heiwado & Co.