Washington, Feb 24 (IANS): Seven US Marines were killed in a mid-air collision of two US military helicopters in southern Arizona, CNN reported Thursday.
The crash took place during routine training operations Wednesday night along the California-Arizona border, the Marine Corps said in a statement.
The collision, which occurred near the Marine Corps Air Station Yuma, involved an AH-1W "Super Cobra" attack helicopter and a UH-1Y "Huey" utility chopper.
"The circumstances are being investigated," it said.