Sailing in Australia’s exclusive economic zone, the three vessels were not breaking international law, but they were unusually far south on an undeclared mission.

The Australian and New Zealand militaries are monitoring three Chinese warships that are moving unusually far south along Australia’s east coast on an unknown mission

The Australian navy is shadowing Chinese warships 150 nautical miles east of Sydney, the furthest China’s navy has sailed down the eastern Australian coast. Two Australian ships are following a Chinese naval task group — comprising two warships and a supply vessel — that appeared off the north-eastern coast of Australia a week ago,