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.

Three Chinese warships have been spotted in international waters off the coast of Australia’s largest city, Sydney, in a rare show of military might that will likely test diplomatic ties between Canberra and Beijing.

China did not formally inform the Defence its three warships off Australian waters were to undertake live fire testing, which forced a warning to commercial flights in the area.