Seven Chinese warships on Saturday left east China's port city of Qingdao for the Sea of Japan where they will join Russian counterparts for a nine-day naval exercise.

The drills, codenamed Joint Sea-2015 (II), will take place from Aug. 20 to 28 in the Peter the Great Gulf, waters off the Clerk Cape, and in and above the Sea of Japan.

This will be the second such China-Russia naval exercise this year.

Earlier reports said navies of the two countries will join forces to simulate anti-submarine combat, air defense and other relevant missions.

A joint beach landing of troops is also planned.

Sources close to the operation said the drills "are not targeted at any third party and are not relevant to regional status-quo."

The Chinese flotilla includes seven surface ships, namely destroyers Shenyang and Taizhou, frigates Linyi and Hengyang, landing ships Changbaishan and Yunwushan and supply ship Taihu.

Six shipborne helicopters, five fixed-wing aircraft, 21 units of amphibious equipment and 200 marines will also join the exercise from the Chinese side.

The Russian navy, meanwhile, will send 16 surface ships, two submarines, nine units of amphibious equipment and 200 marines, among others, to participate in the drills.

The previous China-Russia naval drills, Joint Sea-2015 (I), were held in the Mediterranean Sea in May.