Twenty people were killed in clashes between rebels and Iranian police in the Kurdish-majority western province of Kermanshah, state television reported on Saturday.
"On Friday evening, some armed bandits attacked Ravansar-Paveh police station, killing 10 members of Iran's law enforcement forces," it quoted a police statement as saying.
Ten bandits were also killed in the fighting, the statement added, without identifying the attackers.
The area has witnessed a series of deadly clashes in recent years between the Iranian security forces and the rebel Party of Free Life of Kurdistan (PJAK).
Operating out of rear-bases in neighbouring Iraq, the group is closely allied with the Turkish Kurdish rebel group, the Kurdistan Workers' Party.
Iraq, Iran, Syria and Turkey all have significant ethnic Kurdish minorities.