The soldiers appeared to have been killed in clashes on Monday with "counter revolutionary elements" which the military has already said resulted in the deaths of 10 rebels.

"The commander of the Aba Abdollah al-Hossein second brigade Brigadier General Ali Reza Talaie and the head of intelligence of this unit Ghorban Ali Ebrahimi were martyred, along with their comrades," an army statement said.

It said five other rank-and-file soldiers were killed in the clashes near the town of Salmas in Iran's West Azarbaijan province, 30 kilometres (20 miles) from the border with Turkey.

The statement did not give further details on the rebels but past incidents in the area and its ethnic composition indicate they were linked to Kurdish militants.

West Azarbaijan province has been the scene of regular armed clashes between Iranian security forces and Kurdish militant parties, in particular Pejak, a group linked to Turkey's outlawed Kurdistan Workers' Party (PKK).

Iran is bound by treaty with Turkey to fight the PKK. In return, Turkey has pledged to fight Iran's main armed opposition group, the Iraq-based People's Mujahedeen.

Turkey has praised Iran's efforts to crack down on Kurdish rebels linked to the PKK, who have been waging a deadly armed struggle for self-rule in the southeast of Turkey since 1984.

Turkey and Iran have in turn expressed dissatisfaction with Iraq's failure to expel Kurdish militants from its side of the border and even threatened to launch cross-border raids inside Iraq if Baghdad does not act.

Iranian authorities have regularly accused the United States and Britain of seeking to stir unrest amongst ethnic minorities in its sensitive border areas close to the Turkish, Iraqi and Pakistani frontiers.