A Chinese high-performance fighter intercepted and buzzed a US Navy P-8A maritime patrol and surveillance aircraft on Tuesday in international air space over the South China Sea, the Pentagon confirmed on Friday.

The interception was "very close, very dangerous ... pretty aggressive and very unprofessional," Pentagon spokesman Rear Adm. John Kirby told reporters.

The Chinese aircraft, a Shenyang J-11B Flanker B from the People's Liberation Army Air Force, made a number of close passes to the P-8A Poseidon, a military version of the well-known Boeing 737 jetliner.

The interception took place about 135 miles east of Hainan Island, Pentagon officials said, noting that the area in which, per international law, military activities may be conducted "as an exercise of the freedoms of navigation and overflight."

"On three different occasions, the Chinese J-11 crossed directly under the US aircraft with one pass having only 50-100 feet separation between the two aircraft," the Pentagon said in a statement.

"The Chinese jet also passed the nose of the P-8 at 90 degrees with its belly toward the P-8 to show its weapons load out. In doing so, the [Chinese] pilot was unable to see the P-8, further increasing the potential for a collision," the Pentagon said. "The Chinese pilot then flew directly under and alongside the P-8 bringing their wingtips within 20 feet and then, before he stabilized his fighter he conducted a roll over the P-8 passing within 45 feet."

The P-8A, according to one source, is from Patrol Squadron 45, based at Naval Air Station Jacksonville, Florida, and deployed to the western Pacific, operating from Kadena Air Base on the Japanese island of Okinawa.

The Poseidon is a relatively new aircraft in US Navy service, with deployments beginning only last year.

The latest incident was reminiscent of an affair more than a decade ago when an aggressive Chinese jet pilot buzzed a US Navy EP-3E Aries II spy plane also flying near Hainan Island. In that instance, the Chinese J-8 interceptor collided with the EP-3E. The Chinese pilot was killed, and the damaged EP-3 was forced to make an emergency landing on Hainan Island. The US crew failed to completely destroy the highly-classified contents of their aircraft, which were thoroughly examined by the Chinese.

The EP-3E crew was held by China for 11 days. When Chinese officials refused to allow the aircraft to take off, the Aries was disassembled and returned to the US, where it was not repaired.

The latest incident with the P-8A and J-11B, Kirby said, "is one of the most unsafe intercepts since the 2001 EP-3 collision."

Hainan Island, with numerous airfields and submarine bases, remains an area of interest for the US and other countries in southeast Asia.

"This incident is the most recent in a rising trend of nonstandard, unprofessional and unsafe intercepts of US aircraft that we have observed since the end of 2013," the Pentagon statement said.

"Based on our observations, the Chinese intercepting aircraft appear to have originated from the same unit in Hainan as other close intercepts that occurred in March, April and May. We are concerned that the intercepting crews from that unit are acting aggressively and demonstrating a lack of regard for the safety of our aircrews." ?