China seizes American underwater drone in South China Sea

District of Columbia: A Chinese Navy warship has seized an underwater drone deployed by an American oceanographic vessel in international waters in the South China Sea, triggering a formal diplomatic protest from the United States and a demand for its return, a US defense official told Reuters on Friday.

The incident, the first of its kind in recent memory, occurred on December 15 northwest of Subic Bay off the Philippines just as the USNS Bowditch, an oceanographic survey ship, was about to retrieve the unmanned, underwater vehicle (UUV), the official said, speaking on condition of anonymity.

"The UUV was lawfully conducting a military survey in the waters of the South China Sea," the official said.

"It`s a sovereign immune vessel, clearly marked in English not to be removed from the water - that it was US property."

The "naval glider" was used to test water salinity and temperatures to help in the mapping of underwater channels, news agency AFP quoted an official as saying.

While the probe was a US Navy vessel, it was operated by civilians, the official said.

The Chinese seizure will add to concerns about China`s growing military presence and aggressive posture in the disputed South China Sea, including its militarization of maritime outposts. 

A US think tank reported this week that new satellite imagery indicated that China has installed weapons, including anti-aircraft and anti-missile systems, on all seven artificial islands it has built in the South China Sea.

The United States issued the formal demarche, as such protests are known, through diplomatic channels and included a demand that China immediately return the underwater drone.

The Chinese have acknowledged the demarche but not responded to it, the official added.

The Philippines, Brunei, Malaysia and Vietnam have competing claims in the South China sea, which is laced with the world`s most heavily traveled international trade routes.

While the United States takes no position on sovereignty claims in the South China Sea, it has repeatedly stressed that all maritime claims must comply with international law.

The US military has conducted several "freedom of navigation" operations in which ships and planes have passed close to the sites Beijing claims.

Such missions have drawn howls of fury from China, which accuses Washington of provocation and increasing the risk of a military mishap.

Adding to the tension, Beijing is facing a new US president in Donald Trump, who has questioned longstanding US policy on Taiwan, called Beijing a currency manipulator and threatened Chinese imports with punitive tariffs.

(With Agency inputs)