The Japanese Defence Minister Itsunori Onodera said on Sunday that Tokyo was considering releasing evidence showing that a Chinese frigate locked its fire-control radar on a Japanese ship.

One day earlier, the Chinese Defence Ministry said in a statement that its fire-control radar was not in in use.  Japan and China have seen their ties tense since last September when Tokyo announced it would nationalize some islands in Senkaku or known as Diaoyu in Beijing.