China installs radar in disputed waters: Japanese media

China has installed a radar with potential military functions in a disputed area of the East China Sea, Japanese media said Sunday, in the latest flare-up of tensions between the two countries.

The Japanese foreign ministry said China had placed a surface search radar and surveillance camera on one of its structures in a gasfield which is claimed by both countries, the Nikkei business daily reported.

The ministry on Friday complained to Beijing through diplomatic channels, the newspaper reported.

The paper said it was the first radar unit known to have been installed on any of the Chinese structures in the area, which is believed to be rich in oil and gas deposits.

Tokyo is analysing the radar's capability and is concerned that Beijing could be intending to strengthen its military power in the East China Sea.

The foreign ministry did not immediately respond to requests for comment on the report.

Japan and China agreed in 2008 to jointly develop the undersea reserves in the disputed area, with a ban on unilateral drilling.