The Chinese navy's first aircraft carrier has begun its sea trials, the state-run Xinhua news agency has said.
It quoted military sources as saying that the refitted former Soviet warship left its shipyard in the north-east and the trial "would not take a long time".
The move is likely to raise fresh concerns over China's rapid military build-up.
Beijing is currently involved in several maritime territorial disputes, particularly in the South China Sea.
The aircraft carrier left its shipyard at Dalian Port in northeast Liaoning Province on Wednesday morning, Xinhua reported.
"Military sources said that the first sea trial was in line with the schedule of the carrier refitting project," it said.
"After returning from the sea trail, the aircraft carrier will continue refit and test work." (more)