Ships of the People's Liberation Army navy patrolled the waters near the Diaoyu Islands on Monday after returning from a training exercise in the West Pacific.

The flotilla, two destroyers and two frigates from the Navy's Donghai Fleet, passed through the Miyako Strait and entered the West Pacific for a routine training exercise on Nov 28.

After finishing a series of training operations, the flotilla sailed through a strait near the Yonaguni and Iriomote Islands and arrived in waters off the Diaoyu Islands on Monday morning.

The four warships patrolled the waters in formation in rough weather and heavy seas, according to a Xinhua reporter aboard the frigate Zhoushan.

Qiu Yanpeng, commander of the task force and the Donghai Fleet's vice-commander, said Diaoyu Island and its affiliated islets have been part of China's territory since ancient times.

It is legitimate for China's navy to patrol waters under Chinese jurisdiction and it is the Navy's responsibility to safeguard the country's maritime territory and interests, Qiu said.

Monday's patrol was the third of its kind conducted since Japan stirred up tensions with China over the Diaoyu Islands earlier this year.

Sources with the Ministry of National Defense said a seven-warship task force from the navy's Beihai Fleet patrolled the waters near the Diaoyu Islands on Oct 16.

In late September, Defense Ministry spokesman Yang Yujun confirmed that Chinese naval ships had carried out patrols and military training in the waters earlier that month.

A statement issued by the ministry on Monday said that China will continue naval training in the West Pacific.

The training exercise in the West Pacific was routine and conducted in accordance with the navy's annual training plan, and concerned countries should respect the Chinese navy's freedom of navigation and aviation in line with international law, it said.