Staff writer

ABOARD THE SHIRANE IN THE EAST CHINA SEA -- Japan and South Korea conducted their first-ever joint naval exercise Thursday west of Kyushu, sending a strong warning to North Korea amid growing speculation that Pyongyang will conduct another ballistic missile test-launch.

Thursday's search-and-rescue drill was carried out by three Maritime Self-Defense Force destroyers and two South Korean Navy warships, along with antisubmarine patrol aircraft and helicopters.