File photo shows a bombardment aircraft of the People's Liberation Army (PLA) Air Force participating in a training. Aircraft of the People's Liberation Army (PLA) Air Force flew over the Miyako Strait for the first time on May 21, 2015 for training in western Pacific, a military spokesperson said. [Photo: Xinhua]

In the past year, China's air force held 4 drills over the western Pacific, aimed at enhancing its combat capabilities over long distances and in the open sea.

On March 30, aviation troops of the People's Liberation Army, or PLA, flew to the open sea via the Bashi Channel of Taiwan. This was the troops' first exercise in the western Pacific.

The next drill took place on May 21. PLA aircraft flew over the Miyako Strait. The strait is near Japan's Miyako Islands, which is an international waterway.

The third drill on August 14 involved several types of aircraft flying over the Bashi Channel.

The final drill was led by H-6K medium-long range bombers, and took place on November 27th.

Colonel Han Xudong is a professor at China's PLA National Defense University. He says these drills demonstrated the air force's growing capabilities to protect China's security.

"The fact that the PLA air force was able to complete the exercises far offshore indicated a leveling up of their weaponry, logistic support and combat abilities. All these have showed a rapid improvement in combat capacities of the air force. The open sea drills of the air force came after the PLA Navy's similar operations in the western Pacific, making it possible for our air and navy forces to join hands for future drills in the region and greatly improving our capabilities to protect China's overseas interests."

The PLA has said it plans similar drills in the future, but said they would not target any particular country or region.