GUANGZHOU, Aug. 14 -- The People's Liberation Army (PLA) Air Force conducted a drill involving "multiple types of aircraft" in the western Pacific on Friday, a military spokesperson said.

PLA aircraft flew over the western Pacific via the Bashi Channel and returned on the same day, reaching 1,000 km beyond the First Island Chain, spokesperson Shen Jinke said at a news briefing.

The First Island Chain refers to a series of islands that stretch from Japan in the north to Taiwan and the Philippines to the south.

"[The drill] is in line with international laws and practices, and doesn't aim at any specific country, region or target," Shen said, adding that aviation troops have improved their maneuvering and combat abilities over the open sea.

Shen stressed that open sea drills are a common practice for air forces of coastal countries and "a normal requirement for China's national defense and military development."

According to Xing Hongbo, a military and legal expert, aircraft avoided altitudes designated for civil aviation and didn't affect international flights, and the entire drill was "lawful, open and transparent."

Xing noted that the country's air force soldiers and officers have always respected and obeyed international laws, and each exercise was arranged with full consideration of the law.

Shen revealed that the air force will continue to conduct open sea drills beyond the First Island Chain "based on various conditions."