A Chinese fighter jet and a Royal Australian Air Force maritime patrol aircraft had an “unsafe and unprofessional” interaction as the two operated over the waters of the South China Sea, Canberra officials said Monday.

The incident in the South China Sea on Sunday highlights tension in a region where China is demonstrating its growing military capabilities.

All personnel involved were safe, and the causes of the two crashes were under investigation, the U.S. Navy's Pacific Fleet said.

A U.S. Navy helicopter and a fighter jet crashed separately into the South China Sea within the space of an hour during routine operations conducted from the same aircraft carrier on Sunday, the U.S.