At least 11 Iranian police officers have been killed in separate clashes with armed groups in two of the country's western provinces, local media reports say.
In the first attack on Friday night, armed men killed 10 policemen after they attacked a police station in the town of Ravansar in Kermanshah province, the ISNA news agency reported on Saturday.
Ten "bandits" were also killed in the clash, it was reported.
The report did not give detail on the identity of the attackers, but Iran's Press TV said the men were members of the separatist Party of Free Life of Kurdistan (PJAK).
Kermanshah borders Iraq and is home to many of the Islamic Republic's minority Kurds.
In the second incident, unknown armed men attacked a police base situated on a road in the outskirts of Sanandaj in Kordestan province early on Saturday morning, Press TV said.
During the attack, the armed group killed an Iranian police officer and injured four others, the report said.
Iran's western provinces have been the scene of regular armed clashes between Iranian security forces and Kurdish separatists, in particular PJAK, an anti-Iranian Kurdish group linked to Turkey's outlawed Kurdish Workers' Party (PKK).
The PKK took up arms in 1984 to fight for a Kurdish homeland in southeast Turkey and is recognised by much of the international community as a terrorist group.
Some Iranian analysts said that PJAK rebels had bases in northeastern Iraq from where they operated against Turkey, Iran, and Syria.