WASHINGTON (CNN) -- Two Chinese fishing vessels came "dangerously close" to a U.S. military ship in the Yellow Sea off the coast of China last week -- the fifth such incident in the past few months, two U.S. officials told CNN Tuesday.
The USNS Victorious is an unarmed ocean surveillance ship operated by a civilian crew.
The officials -- who could not be identified because the incident has not yet been formally announced -- said the two Chinese boats approached the USNS Victorious, a military sealift command ship, in international waters Friday in the Yellow Sea, which lies between China and North and South Korea.
Over a period of several hours, the officials said, the Chinese vessels repeatedly came close to the Victorious in what was described as deliberate maneuvers -- once coming within 30 yards of the U.S. vessel.
Both officials said the Chinese vessels came to a dead halt in front of the Victorious at one point, in heavy fog, causing the U.S. ship to have to come to a dangerous sudden stop. The officials did not know the exact size of the Chinese ships but described them as being smaller than the 235-foot long U.S. vessel.
The crew of the Victorious turned its fire hoses on to keep the Chinese ships away but did not directly spray them at the smaller boats, one official said. The Victorious also sounded its danger alarm system and radioed for assistance to a larger Chinese fisheries service vessel nearby. That vessel did shine a light on the small Chinese vessels but took no further action, the official said.
The USNS Victorious is an unarmed ocean surveillance ship operated by a civilian mariner crew working for the Military Sealift Command. The mission is to conduct authorized undersea listening operations in international waters, according to the U.S. Navy. There is video of this latest incident, but it has not been released by the Pentagon.
The Victorious was involved in another incident with a Chinese ship on March 4 in the Yellow Sea, when a Chinese Bureau of Fisheries Patrol vessel used a spotlight to illuminate the Victorious and crossed the U.S. vessel's bow "at a range of about 1,400 yards in darkness without notice or warning," according to a Pentagon statement.
The following day, a Chinese Y-12 maritime surveillance aircraft conducted 12 fly-bys of the Victorious at an altitude of about 400 feet and a range of 500 yards, the Pentagon said.
On March 6, a Chinese frigate approached the USNS Impeccable, another U.S. ocean surveillance ship, "and proceeded to cross its bow at a range of approximately 100 yards," the Pentagon said. Two hours later, a Chinese Y-12 aircraft conducted 11 fly-bys of the Impeccable at an altitude of 600 feet and a range from 100-300 feet, the statement said.
Two days later, five Chinese ships surrounded and harassed the Impeccable in the South China Sea. The crew of the Impeccable turned its fire hoses on the Chinese boats, which also moved in front of the U.S. vessel and dropped pieces of wood in the water. The United States protested the actions to Beijing as "unprofessional."
Last week's incident came soon after U.S. Chief of Naval Operations Adm. Gary Roughead returned from a visit to China last month. He was there to discuss the safety of U.S. and Chinese maritime operations.
After the Impeccable incidents, the U.S. Navy provided armed warships to escort some USNS ships in the region, but as one of the officials said, "it's international waters, we should not have to do that."
The Chinese claim much of those waters as an economic zone over which they have sole authority.