A U.S. Navy MH-60R Sea Hawk helicopter and an F/A-18F Super Hornet fighter jet crashed in the South China Sea within 30 minutes of each other on Sunday, though all crew members were safely rescued.

Both aircraft were operating from the USS Nimitz during routine missions, and the causes of the incidents are under investigation.

The South China Sea, a strategic shipping route, is subject to overlapping territorial claims by China and several neighboring countries, heightening regional tensions, Axios has reported.

The crashes occurred as President Trump visits Asia, where he is expected to meet Chinese leader Xi Jinping this week.