It is highly likely the recent collision of a Chinese submarine and an underwater sonar array towed by a US warship in the South China Sea was due to misjudgment of distance, Chinese military experts said.

The conjecture is in line with the United States view of "inadvertent encounter".

The collision occurred last Thursday as the destroyer USS John S. McCain was sailing in the sea, CNN television reported on Friday.

Its sonar array, used to listen and locate underwater sounds, was damaged in the incident, but fortunately the sub and ship did not collide, an unnamed military official told CNN.

The official said the US Navy does not consider the incident a harassing move by Beijing, as it would have been extremely dangerous had the array got caught in the submarine's propellers.

So far, both China's Ministry of National Defense and the Pentagon have yet to comment on the incident, while most US media have downplayed it with short reports.

"The destroyer USS John S. McCain isn't a professional anti-sub ship, while such US destroyers stopped carrying sonar arrays after the collapse of the former Soviet Union," said Yin Zhuo, a senior researcher with the People's Liberation Army Navy Equipment Research Center.

"According to the CNN report, the US destroyer seems to have failed to detect the sub, while the sub set its distance from the US ship based on the assumption it wasn't carrying sonar arrays. It's highly possible that's the reason for the incident," Yin said.

The submarine is likely not damaged, as the sonar array is quite thin and soft, he added.

Philippine Navy spokesman Lt. Col. Edgard Arevalo said on Saturday that to their knowledge the US warship was in international waters at the time of the collision.

According to media reports, the US destroyer, along with three other US warships, was on an annual joint exercise in the South China Sea with navies from six Southeast Asian countries, including the Philippines and Malaysia.

One of the four US ships is the USNS Chung-Hoon, one of the world's most advanced destroyers.

According to the Kuala Lumpur Security Review, the participation of four advanced USNS ships is aimed at familiarizing the US navy with the situation in the South China Sea and shows the possibility of the US Navy's joint combat role with Southeast Asian nations.

Major General Luo Yuan, a senior researcher with the Academy of Military Sciences in Beijing, said though the collision was accidental, the existence of US ships in the South China Sea is cause for potential incidents.

"The best way to avoid such collisions is for the Pentagon to stop its unfriendly moves toward China in this region," he said.

(China Daily June 15, 2009)