1 of 2 | Japanese national flag flies in front of the National Emblem of the People's Republic of China on the Great Hall of the People. Photo by HOW HWEE YOUNG / EPA

Aug. 11 (Asia Today) -- Chinese authorities have detained several Japanese business people as Beijing intensifies export controls on rare earths and dual-use goods bound for Japan, prompting Tokyo to warn Japanese companies operating in China to exercise greater caution.

Several employees and executives connected to Japanese companies have been detained in cases related to China's restrictions on exports of rare earths and other products with both civilian and military applications, according to Japanese media reports Tuesday.

Chinese authorities have also increased inspections at Japanese business facilities and questioning of company officials.

In one case, a Japanese national reportedly traveled from Japan to China in response to a request for questioning by Chinese authorities and was detained after entering the country.