China's two Sukhoi Su-30 intercepted an American aircraft even thought it was following international law. According to officials, United States' sniffer aircraft was on a routine mission of detecting radiation, over the East China Sea.

United States' WC-135 Constant Phoenix plane was on a routine mission on Wednesday when two Chinese fighter planes, Sukhoi Su-30, intercepted it. According to BBC, the WC-135 Constant Phoenix was checking for signs of radiation due to nuclear activity over the East China Sea, by 'sniffing' the atmosphere for signs.

Though the officials have not revealed whether the interception was unsafe, they have stated that it was extremely 'unprofessional' due to the speed, proximity and the drills of the Chinese aircraft. More so as the U.S aircraft was flying as per international law. The spokesperson of the Air Force, Lt Col Lori Hodge has said that the issue has been raised and it is "being addressed with China through appropriate diplomatic and military channels."

Notably, due to increased US activity over internationals waters and off the coast of China, the tension levels have increased. This is due to the disagreement of China, which claims territorial right over the region, and the US, which claims the area to be international seas or airspace, Bloomberg reported. Though China has not said anything regarding the recent incident, but China suspects that the US carries out such investigation regularly. 

This is not the first time that Chinese fighter planes have stopped a US aircraft. In May 2016, another US aircraft was intercepted over the South China Sea by two Chinese aircraft. Moreover, in the past as well, United States used sniffer aircraft to detect possibilities of nuclear tests in North Korea.