A fleet of Chinese naval vessels sailed out of Qingdao port in eastern China heading to the Sea of Japan for joint exercises with Russia, state media reported on Tuesday.

Four destroyers, two escort vessels and a supply ship left the port on Monday, marking the largest number of vessels the Chinese navy has ever sent to take part in joint military drills with foreign countries, state-run Xinhua news agency said.

A total of 18 vessels, one submarine, three fixed-wing planes, five carrier-based helicopters and two teams of special forces from the two countries will participate in the exercises, that will kick off on Friday, Xinhua reported.

The eight-day manoeuvres will focus on joint maritime air defence, joint escorts and marine search and rescue operations, it added.