Japan has protested to China over a surface radar found to have been installed on one of the Chinese gas drilling platforms in the East China Sea area where the countries have overlapping economic claims, a Japanese government source said Sunday. 
The source said that the radar is for detecting ships and is not powerful enough to be used for military purposes, though concerns remain about China's use of the structures as a military post in the future, according to Japan's (Kyodo) News Agency. 
China has drilling platforms and foundations near the median line between the shorelines of the two countries.

Source: QNA