On Friday, the U.S. Pacific Command announced that one of its patrol aircraft had a “close encounter” with a Chinese plane over the South China Sea. The Pentagon initially classified the encounter as “unsafe” but later walked this judgment back.

The encounter occurred on Wednesday, in international airspace over open waters of the South China Sea, according to Pacific Command statements quoted by the Associated Press.

Pacific Command spokesman Robert Shuford said a U.S. Navy P-3C “Orion” plane was on a routine mission when it encountered a Chinese KJ-200 early warning aircraft.

The P-3C is used for surveillance and submarine detection, while the KJ-200 is roughly comparable to an American AWACS plane, an airborne radar platform designed to coordinate the activity of other aircraft.

Reuters clarifies that the planes came within 1,000 feet of each other “in the vicinity of the Scarborough Shoal, between the Philippines and the Chinese mainland.”

“It crossed the nose essentially of the P-3 and caused the P-3 to have to make an immediate turn. We’re going to review the incident. We have channels to discuss it,” Pentagon spokesman Capt. Jeff Davis said on Friday.

“There’s just nothing that we see that would indicate that they did this intentionally. There’s no presence of information that would indicate intent,” Davis added.

When a reporter at the Pentagon briefing asked why a Chinese early-warning aircraft would have difficulty detecting a rather large American plane until they came within 1,000 feet of each other, Davis laughed and said, “That’s a very, very good point. Look, these things do happen.”

He said that the incident was under review by the chain of command, and they would “make appropriate judgments and raise it with the Chinese government if it needs to be.”

The Scarborough Shoal has been the scene of some tense encounters between China and the Philippines. It was the subject of the lawsuit that ultimately prompted the Permanent Court of Arbitration at the Hague to reject China’s expansive territorial claims in the South China Sea.

Last September, Filipino fishermen complained about a growing number of intimidating Chinese ships appearing in the area, including the type of barges China uses to create man-made islands for military installations.

This week, Philippines Defense Secretary Delfin Lorenzana said he expected China to create an artificial reef in the Scarborough Shoal and effectively annex the disputed area — a development the South China Morning Post notes the United States “has said it is not prepared to accept.”

Lorenzana stated Chinese construction in the Scarborough Shoal was a “red line” for the Americans and also “unacceptable” to the Philippines.

“If we allow them, they will build. That’s very, very disturbing. Very much [more] disturbing than Fiery Cross because this is so close to us,” Lorenzana said. The SCMP notes that such a move could position Chinese fighters and missiles within range of American forces stationed in the Philippines and also prevent the naval forces of other countries from using the area.

The Chinese Defense Ministry insists that its pilot followed “legal and professional measures” during the encounter with the U.S. Navy aircraft.

Reuters relates a quote from an anonymous Defense Ministry official who blamed the United States for the encounter: “We hope the U.S. side keeps in mind the present condition of relations between the two countries and militaries, adopts practical measures, and eliminates the origin of air and sea mishaps between the two countries.”