ZHOUSHAN, Zhejiang - A fleet of the Chinese People's Liberation Army (PLA) Navy on Monday morning left port in East China's Zhejiang province for the West Pacific region on a routine drill.

The fleet is composed of two frigates, the Yiyang and Changzhou, both from the Donghai Fleet of PLA Navy.

As part of annual routine training, the fleet will conduct combat readiness patrols; comprehensive attack and defense routines in open sea; helicopter drills; and non-combat military operations among others.

Yan Zhengming, commander of the fleet, said drills in open sea are common practice to improve combat capability.

The PLA Navy has organized several drills in open sea in the West Pacific this year.

The Yiyang and Changzhou came into service in 2010 and 2011 respectively. The two frigates joined the escort mission in the Gulf of Aden from July 2012 to January 2013.