March 9 (Bloomberg) -- Five Chinese vessels in a possibly coordinated effort yesterday “shadowed and aggressively maneuvered in dangerously close proximity” to a U.S. Navy surveillance ship in international waters, the Pentagon said.

Two of the vessels closed to within 50 feet (15 meters) of the USNS Impeccable, waving Chinese flags and telling the U.S. ship to leave the area, according to a Defense Department statement issued today. The Impeccable sprayed water from its fire hoses at one of the boats to protect itself.

The incident took place eight days after the U.S. and China agreed to resume exchanges of military officers for information sharing after China in October froze some contact to protest arms sales to Taiwan.

The U.S. Embassy in Beijing lodged a protest during the weekend with Chinese officials over the incident, State Department spokesman Robert Wood said today.

“We felt that our vessel was inappropriately harassed,” Wood told reporters in Washington.

Yesterday’s encounter took place in the South China Sea, about 75 miles south of Hainan Island, and included a Chinese Navy intelligence ship, the Pentagon said. The incident was preceded by days of increasingly aggressive conduct by Chinese vessels, the Defense Department said.

“We’re going to continue to operate in those international waters, and we expect the Chinese to observe international law around that,” White House press secretary Robert Gibbs said in Washington.

A Chinese Embassy spokesman in Washington, Wang Baodong, didn’t return two phone calls or an e-mail seeking comment.

Hong Kong-based Phoenix Television cited unnamed embassy officials as calling on the U.S. to stop illegal surveying activities in China’s exclusive economic zone. The officials called the U.S. charges “groundless,” Phoenix reported.

No one picked up two calls to the news department of the Ministry of Defense in Beijing during business hours.

Vessel Challenged

On March 7, what the Pentagon described as a Chinese intelligence collection ship challenged Impeccable via bridge- to-bridge radio broadcast, calling the U.S. vessel’s operations illegal and directing it to leave the area or “suffer the consequences,” the Pentagon said.

Two days earlier, a Chinese frigate crossed Impeccable’s bow at a range of about 100 yards, according to the Pentagon’s account. Less than two hours later a Chinese Y-12 surveillance aircraft made 11 fly-bys of Impeccable, and the frigate crossed Impeccable’s bow again at a range of 400 to 500 yards.

On March 4 a Chinese Bureau of Fisheries Patrol vessel used a high-intensity spotlight to illuminate the entire length of the ocean surveillance ship USNS Victorious several times, the U.S. said. The vessel then crossed Victorious’s bow in darkness, without notice. A Chinese Y-12 made 12 passes near Victorious the next day.

Impeccable and Victorious are part of the Military Sealift Command. Impeccable carries a crew of 25 civilian mariners and 25 military personnel, and Victorious has about 18 crewmembers, according to Navy Web pages on the vessels.

To contact the reporter on this story: Tony Capaccio at the Pentagon at at acapaccio@bloomnberg.net

Last Updated: March 9, 2009 23:36 EDT