Japanese firms take protective action amid protests

The problems over the disputed islands, known as Diaoyu in China and Senkaku in Japan, are souring relations between the two countries.

As China and Japan clash over disputed islands, the impact on business looks set to continue.

Japan has warned its citizens about large-scale protests in China again on Tuesday, and companies have said they are monitoring the situation.

Trade between Japan and China grew by more than 14% in 2011 to a record $345bn and China is Japan's biggest trading partner.

The BBC's Martin Patience has more from Beijing.