20 May, 2017
On Wednesday, two Chinese People's Liberation Army Air Force (PLAAF) Su-30 fighters intercepted a U.S. Air Force Boeing WC-135 Constant Phoenix aircraft over the Yellow Sea, according to U.S. authorities.
Martin says the WC-135 is the plane the US uses to sample air for signs of a nuclear explosion, and it is regularly flown in the area.
As for Wednesday's intercept, the AP quoted Hodge as saying that it's "being addressed with China through appropriate diplomatic and military channels".
The incident was the second between US and Chinese aircraft this year. The incident reportedly took place in worldwide airspace.
The incident is the latest of encounters over territories China that insists are its own, claims the U.S. opposes.
Japan said it was the first time China has used an unmanned aircraft in the long-simmering dispute over the islands, called the Senkaku by Japan and the Diaoyu by China.More news: Stars Wars fans say, 'May the 4th be with you'
In April 2001, another intercept of a US EP-3E spy plane by a Chinese F-8 fighter in the same area resulted in a collision that killed the Chinese pilot and forced the US plane to make an emergency landing at a base on Hainan.
She said the WC-135 was carrying out a routine mission at the time and was operating in accordance with worldwide law.
Although China says it respects freedom of navigation in the strategically vital area, it objects to us military activities, especially the collection of signals intelligence by USA craft operating near the coast of its southern island province of Hainan, home to several military installations.
Mid-air interceptions occur routinely in global airspace, but the United States military will often call out foreign pilots if it judges the maneuvers to be risky or unprofessional.
In February, a Chinese KJ-200 aircraft came within 1,000 feet of a US Navy P-3 Orion aircraft over the China Sea. The official said then that similar incidents involving Chinese and American aircraft were infrequent, with only two having taken place in 2016.