The governor general of West Azerbaijan province, Vahid Jalalzadeh, said that during clashes between Iranian forces and members of PJAK, "the person behind the assassination of Khoy prosecutor was identified and arrested."

He said the clashes took place Monday night and added that several PJAK members were killed in the fighting which occurred close to "a border."

Jalalzadeh did not reveal on which border the clashes occurred as West Azerbaijan has borders with Iraq, Turkey and Azerbaijan.

On January 19, Fakhrali Nikbakht, a local interior ministry official said that four people had been arrested over the gunning down of Vali Haji-Gholizadeh, the prosecutor of the northwestern town of Khoy.

Iranian officials had previously claimed that the prosecutor was killed by PJAK.

PJAK, the Party of Free Life of Kurdistan, is closely allied with the Turkish Kurdish rebel group, the Kurdistan Workers' Party (PKK), which is listed as a "terrorist" group by Ankara and much of the international community.

Northwestern Iran, which has a sizeable Kurdish population, has seen deadly fighting in recent years between Iranian security forces and PJAK members as well as other Kurdish rebels operating from bases in neighbouring Iraq.

Iraq, Iran, Syria and Turkey all have significant ethnic Kurdish minorities.