"The government of Finland is deeply concerned over the harassment of Iranian human rights activists and journalists. Iran is expected to observe in full the international human rights agreements to which the country has committed itself," the ministry said in a statement.
The foreign ministry summoned Iran's charge d'affaires Hossein Ali Zadeh on Thursday, it said, adding this was not the first time the Iranian representative was summoned over human rights issues.
In recent weeks, Finland has become particularly concerned about the violent suppression of demonstrations, increased harassment of human rights activists and the treatment of the Bahai minority, it said.
Pertti Torstila, secretary of state at the foreign ministry, emphasised the importance of religious freedom and freedom of opinion and said he was dismayed by the detention of members of the Bahai faith.
"Finland condemns the use of violence against demonstrators exercising their freedom of speech and freedom of assembly. Every person detained in connection with demonstrations should be guaranteed a fair trial," the ministry said.
Earlier this week, Human Rights Watch said Iran had launched "the most widespread crackdown" in a decade after its disputed presidential election in June and the large protests it provoked.
President Mahmoud Ahmadinejad's June re-election has triggered a string of protests over the past seven months, with opposition demonstrators defying official warnings to stay off the streets.
Dozens of leading government critics, including human rights lawyers, have been rounded up and at least two journalists working with foreign outlets have been detained.
