ABOARD XI'AN DESTROYER -- Two Chinese Navy fleets began a confrontation drill in the Sea of Japan Thursday, according to a military source Friday.

One fleet included the missile destroyer Xi'an, missile frigate Hengshui and supply ship Gaoyouhu. ALl of the three have just wrapped the Rim of the Pacific 2016 (RIMPAC 2016) multinational naval exercise, the Navy source said.

The rival fleet consisted of several warships from the Navy's Donghai Fleet.

Foreign aircraft attempted surveillance during the drill and were met with the proper response from the Chinese warships, the source said.

The drill, arranged according to the Navy's annual training plan and a common practice seen across the world, is in line with the international law and practice, the source noted.