ZHOUSHAN, Zhejiang - The Chinese navy will conduct a joint exercise in the East China Sea with the country's fishery administration and marine surveillance agency on Friday, navy sources announced on Thursday.

A total of 11 vessels from the Donghai Fleet of the People's Liberation Army (PLA) Navy, the fishery administration and marine surveillance agency will take part in the exercise along with eight aircraft, according to a statement from the fleet.

The exercise is aimed at improving coordination between the navy and administrative patrol vessels and sharpening their response to emergencies in missions to safeguard territorial sovereignty and maritime interests, the statement said.

When carrying out missions in disputed waters, patrol vessels of the fishery administration and marine surveillance agency have been stalked, harassed and even intentionally interfered with by foreign vessels, greatly challenging their duties, it added.

During the exercise, administrative vessels will practice patrol voyages with the backup of the navy vessels, and contingency plans will be tested.

The PLA navy has conducted several joint exercises with the fishery administration and marine surveillance agency in the past.