A pair of Chinese fighter jets intercepted a U.S. Air Force surveillance plane flying above East China Sea on Wednesday, military officials said.
The American plane, WC-135 Constant Phoenix, was doing its routine mission of “sniffing” the atmosphere for signs of nuclear activity when the interception occurred.
In a statement, Pacific Air Forces spokeswoman Lt. Col. Lori Hodge characterized the move of the two Chinese Su-30 fighter jets as unprofessional “due to the maneuvers by the Chinese pilot, as well as the speeds and proximity of both aircraft.”
The Chinese jets appeared 150 feet off the WC-135, with one flying upside down directly above the American plane, an official told CNN.
Hodge maintained that the U.S. plane was operating in accordance with international law. “U.S. military aircraft routinely transit international airspace throughout the Pacific, including the East China Sea. This flight was no exception,” she said.
The WC-135 has been used in the past to collect evidence of possible nuclear activity conducted by North Korea.
In 2013, China mapped an air defense identification zone over a vast area of the East China Sea, USA Today cited. Through this, China demanded foreign aircraft to identify their purpose and obey Chinese instructions.
The U.S., however, refused to recognize the zone and called it illegitimate. It is unclear whether Wednesday’s incident took place there. For now, officials are addressing it through “appropriate diplomatic and military channels,” Hodge pointed.
The Wednesday incident is the second between Chinese and U.S. planes this year. The first encounter occurred in February between a Chinese surveillance aircraft and a U.S. Navy P-3 Orion aircraft, CNN noted, which officials determined as “unsafe.”