Tokyo: A Japanese defence helicopter carrying four crew members has lost contact during flight training in central Japan.

Defence officials say the UH-60J lost contact today evening while flying over the Pacific Ocean about 30 kilometres (18 miles) south of Hamamatsu, a coastal city in central Japan.

Officials say a search and rescue effort is underway. So far, there has been no sign of the helicopter or its crew members.

No further details were available.

In August, another defence helicopter, a SH-60J, crashed off the northern Japanese coast, leaving three of its four crew members missing.