A fleet of Chinese and Russian navies, with three warships from each side, arrived at a joint drill area on Tuesday to conduct live-fire exercises, a move to ensure both sides' maritime interests by tackling new challenges and threats in the region.

The six-day drill has formally entered the live-fire stage, experts said.

Both navies will begin exercises including defense of air routes and maritime traffic routes, search and rescue operations and anti-submarine tactics, as well as practice on air, sea and underwater targets with cannons of various calibers on Wednesday and Thursday.

The joint drills, taking place in the Yellow Sea from April 22 to Friday, involve 25 naval vessels, 13 aircraft, nine helicopters and two special fighting groups, making it the largest joint navy drill between the two nations in recent years.

Four Russian warships from the Pacific fleet, including the aircraft carrier Varyag, are participating in the drills. Missile destroyers, missile frigates, missile boats, a support vessel and a hospital ship gathered from China's side.

The exercises are practical and advanced since both navies have devoted their main forces, such as China's Harbin guided missile destroyer and Russia's Varyag, said Zhang Junshe, deputy director of Naval Military Studies Research Institute.

Li Jie, a researcher with the same institute, told Chinese media that both countries have displayed more technologically-advanced weapons compared with the military exercise in 2005.

China and Russia have held four military exercises since 2005, some of which have involved other countries.

People's Liberation Army Navy Commander Wu Shengli said on Tuesday that the first navy drill between Chinese and Russian navies could start a regular cooperation and more diversified joint exercises under the strategic partnership.

However, the drill has unsettled China's neighbors, as another drill is being conducted by the Philippines and the United States near the South China Sea.

The PLA Daily said on Monday that unnecessary concerns over the drill could become an obstacle to forging even closer ties between China and Russia and the development of both countries.

The drill no longer focuses as usual on anti-terrorism but on safeguarding regional security, said Liang Fang, a professor at the Strategic Research Institute at the National Defense University of the PLA.

"Both China and Russia are strong maritime powers that want to use the drill to ensure the safety of their maritime territories and sea lines of communication," she said.

"The defensive exercises are common and indispensable for those close countries to coordinate their actions with each other," she added.

"Besides, this navy drill, though the biggest one between the two countries so far, is smaller than those conducted by the US and its allies."

The US and the Philippines' military exercises are scheduled to last until Friday. Philippine officials have said the exercises are not linked to the Huangyan Island standoff and are not meant to provoke China.

Philippine Department of National Defense also said on Monday that there was nothing unusual with the naval exercises between China and Russia.

Contact the writer at [email protected]