The US Marine Corps said that 2 pilots were killed after their helicopter crashed in Yuma, Arizona.

Iran Press/America: The Marine Corps Air Station said in a statement on Sunday that the crash occurred during a routine training mission.

According to the statement, the pilots of the AH-1Z Viper were conducting a routine training mission as part of the Weapons and Tactics Instructor (WTI) course 2-19, Fox News reported.

The cause of the crash is under investigation.

"The names of the pilots who were killed have not been released and will be withheld until 24 hours after next-of-kin notification," officials said.

The station is located about 2 miles from Yuma and the 1,300-square-mile training ground is one of the world's largest military installations. 101/207

Read more:

One dead after helicopter crashes into Virginia home