Two Chinese aircraft carriers were spotted conducting simultaneous operations in the Pacific for the first time, in a move that Japan’s defence minister said signified Beijing’s intention to further widen its capabilities beyond its borders.

The operations were a “routine training” exercise that did not target specific countries or regions, Wang Xuemeng, a spokesperson for the Chinese Navy, said in a statement, however.

Since May, China has been flexing its muscles by sending an unusually large number of naval and coast guard vessels through a swathe of East Asian waters, according to security documents and officials, in moves that have unnerved regional capitals.