A fighter jet and a helicopter from the aircraft carrier USS Nimitz crashed into the South China Sea within 30 minutes of each other on Sunday afternoon, but nobody was hurt in what analysts called a “remarkable coincidence.

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.

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.

Philippine, American, Japanese, Canadian and French forces held surface warfare drills in the South China Sea this week in Manila’s latest multilateral naval exercise. The combat training activities off Western Palawan are under Sama Sama,