Chinese surveillance aircraft and unmanned aerial vehicles have been conducting reconnaissance flights around the Philippine Sea and off the coast of Taiwan over the past few days, according to releases by Japan’s Joint Staff Office.

China, which claims almost the entirety of the South China Sea, has been involved in an increasingly tense stand-off with the Philippines.

The standoff over Sandy Cay, which lies close to military outposts built by both Beijing and Manila, was the latest between the two nations.