The rebels were only described as being "counter-revolutionaries" in the report, which said the violence happened on Tuesday near the town of Khoy where security forces have been battling Kurdish separatists for years.

The latest unrest came after Iranian armed forces arrested the alleged assassin of Khoy's prosecutor, Vali Haji-Gholizadeh, in January after clashes with Kurdish rebels.

Officials had previously said the prosecutor was killed by the Party of Free Life of Kurdistan, or PJAK.

The group is closely allied with the Kurdistan Workers' Party, or PKK, which operates in Turkey and is listed as a "terrorist" group by Ankara and much of the international community.