TEHRAN, Iran

Five people were killed Sunday when an Iranian helicopter crashed in the Caspian sea.

The mayor of the northern city of Behshahr, Sayyid Khaliq Sajjadi, told state television the helicopter of the National Iranian Oil Company had crashed when it was on a mission to carry an injured person from an oil platform.

He said investigation was underway to determine the cause of the crash.

Reporting by Mustafa Melih Ahishali; Writing by Ali Abo Rezeg