Japan condemns China radar lock
6 February 2013 Last updated at 12:10 GMT
Japanese Prime Minister Shinzo Abe has condemned the decision by a Chinese Navy frigate to put a radar lock on a Japanese ship, calling it "a dangerous act".
The incident happened near a group of islands in the East China Sea, which are controlled by Japan but the ownership of which is disputed by both China and Taiwan.
Rupert Wingfield Hayes says it is the second such radar lock on Japanese craft in recent weeks.