Australian Defense Minister Peter Dutton called the presence of a Chinese spy vessel off the coast of Western Australia an act of aggression, Reuters reported.

Australia tracked a scout ship last week as it sailed past the Harold E. Holt Naval Communications Station at Exmouth, which is used by Australian, US and allied submarines.

In Australia, national elections will be held on May 21, and allegations of a national security threat from China have become the main topic of the election campaign.

In recent years, Chinese Navy ships have been tracked several times off the northern and eastern coasts of Australia.

The Australian Department of Defense said in a statement that a Dongdiao-class auxiliary reconnaissance ship named Haiwangxing sailed along the west coast, crossed the Australian exclusion zone on May 6, and approached the communications station within 50 nautical miles on May 11.