The defense ministries of China and Russia say their air forces have staged another joint aerial patrol over the Sea of Japan and the East China Sea.

The ministries announced that a seventh combined operation of its kind took place on Thursday. The previous one took place in June.

The Russian defense ministry said the latest patrol involved bombers and fighters from both countries, including Russia's Tupolev-95 and Sukhoi-35, as well as China's Hong-6K.

The ministry said the aircraft acted in strict compliance with international law and did not violate the airspace of foreign states.

It added that the patrol proceeded in line with a military cooperation plan between the two nations and was not targeted at any third country.

The South Korean military reported on the patrol prior to the Chinese and Russian announcements. It said two Chinese and four Russian military aircraft had flown inside South Korea's air defense identification zone over waters off its eastern coast between 11:53 a.m. and 0:10 p.m. on Thursday.

A joint statement issued after a summit between Chinese President Xi Jinping and Russian President Vladimir Putin in March included an agreement to conduct joint patrols and military drills on a regular basis.