An Iranian army helicopter crashed in bad weather in a mountainous region near northern Iraq, killing six military personnel, Iranian media reported on Saturday.
Five people were injured in the crash, which happened during manoeuvres involving Iran's elite Revolutionary Guards on Friday, the ISNA news agency reported.
Mohammad Hadisar, governor of the northeastern city of Piranshahr, said the helicopter came down while transporting troops and equipment and blamed it on the weather and a "technical problem", ISNA said.
Another Iranian news agency, Mehr, said it crashed during a military operation against the Party of Free Life of Kurdistan (PJAK), an Iranian offshoot of the Kurdistan Workers Party (PKK) which is fighting for Kurdish autonomy in southeastern Turkey.
Mehr also said the helicopter crashed because of bad weather and strong winds but added the armed forces had inflicted damage against the rebel PJAK during operations in the past few days.
In February, Iranian media said at least 13 soldiers, including two Revolutionary Guards commanders, were killed when a military helicopter crashed near the border with Turkey.
Iranian media also blamed the February crash on bad weather, but Iranian Kurdish rebels said they had shot the helicopter down. PJAK rebels have bases in the remote mountains of northeastern Iraq from where they have launched attacks.
Various Iranian Kurdish rebel groups have fought a low-level conflict against Tehran for many decades, complaining of neglect and discrimination by the central government.
The Revolutionary Guards are an ideologically driven force, with a separate command structure from the regular military.