- Photos from Japan's Defense Ministry show fighter jets and helicopters on the Liaoning as it sails with five other naval ships.
- Sailing with a greater range of aircraft on board shows a complete formation combat system has been formed, one commentator says.
China's first aircraft carrier, the Liaoning, has conducted drills east of Okinawa involving fighter jet and helicopter operations after entering the Pacific Ocean, indicating increased combat capability, an observer said.
Six Chinese naval ships — the Liaoning, a Type 055 destroyer, a Type 052D destroyer, two Type 054A frigates and a Type 901 supply ship — sailed in waters about 300 km (186 miles) east of Kitadaitojima in Okinawa on Sunday, Japan's defence ministry said.
Photographs released by the ministry showed that J-15 fighter jets and Z-9 and Z-18 helicopters were on board the Liaoning, and one photo showed a J-15 taking off from the carrier.
Japan sent its Izumo destroyer and fighter jets to monitor the Chinese fleet.
The Liaoning last week sailed through the Pacific Ocean for a high-seas training exercise.
The aircraft carrier — accompanied by the Nanchang, a Type 055 destroyer; the Rizhao, a Type 054A frigate; and the Hulun Lake supply ship — was spotted about 350 km west of the Danjo islands last Wednesday, then crossed the Miyako Strait to enter the Pacific the following day.
Japan's navy also said that it had spotted the Type 052D guided-missile destroyer Xiamen passing through the Miyako Strait.
Commentator and former Chinese military instructor Song Zhongping said the latest drill showed the Liaoning had acquired combat effectiveness with more types of aircraft on board.
"There is also a different range of aircraft, including fighter jets and early-warning aircraft such as the Z-18, which means that a complete formation combat system has been formed," he said. "It has relatively strong defensive capabilities for autonomous operations in far seas and air."
Collin Koh, a research fellow with the S. Rajaratnam School of International Studies in Singapore, said the Liaoning could carry up to 24 J-15 fighter jets and an assortment of helicopters.
"It's after all mainly for training and to set the foundation for future designs," he said.
The Shandong — China's first domestically built carrier, commissioned two years ago — has also left its home port on the southern island province of Hainan for "combat-oriented exercises" in the South China Sea, Communist Party mouthpiece People's Daily reported on Sunday.
Drills would include fighter-jet landings, damage control and maritime search and rescue, according to the report, which did not disclose the location of the exercises or when they would take place.
Military observers said the two aircraft carriers could soon be operating together to deal with targets such as the United States and Taiwan.
China is building a third aircraft carrier that is believed to be bigger and more advanced than the active warships. According to commercial satellite images, considerable progress has been made on the vessel at a Shanghai shipyard and its launch could be three to six months away.
Koh said the Type 003 aircraft carrier would have aviation capacity closer to those of US supercarriers.
Additional reporting by Amber Wang.