PLA warships transited sensitive international waterways off southwestern Japan twice this week, a rare move seen as a clear warning to Tokyo over its recent actions relating to Taiwan.

The transits marked the start and end of exercises in the western Pacific, outbound through the Yokoate Channel on Sunday and back via the Yonaguni-Iriomote Waterway on Wednesday.

In a statement on Wednesday, the Eastern Theatre Command of the People’s Liberation Army said: “[We] have organised the 133rd Fleet to complete training exercises in the western Pacific, returning via the Yonaguni-Iriomote Waterway, effectively testing the troops’ long-range operational capabilities.”

The strip of water lies between Iriomote Island and Yonaguni – Japan’s westernmost island sitting just 110km (68 miles) from Taiwan.

This is the first publicly recorded instance of PLA warships operating in the waterway.

Song Zhongping, a military analyst and former PLA instructor, views the PLA transits as a “warning to Japan”.