QINGDAO -- A flotilla of the People's Liberation Army (PLA) Navy has completed the year's first open-sea training exercise in the West Pacific Ocean and returned to the port city of Qingdao on Friday.

During the 18-day training exercise, the flotilla patrolled the South China Sea and conducted a joint anti-submarine exercise.

The fleet was followed by foreign aircrafts and warships for much of the time, according to a Xinhua reporter aboard one of the flotilla vessels.

The flotilla comprises three ships -- DDG-113 Qingdao and two frigates FFG-53 Yantai and FFG-546 Yancheng -- carrying three helicopters. They are all from the North China Sea Fleet under the PLA Navy.

It sailed through the Yellow Sea, the East China Sea, the Miyako Strait, the Bashi Channel and the waters off the eastern coast of Taiwan. The journey was more than 5,800 nautical miles and lasted for 408 hours.

More than 700 naval officers and soldiers participated the exercise, which was commanded by Vice Admiral Tian Zhong.