Iran has arrested more than 20 people for "disruptive acts," including reportedly members of its ostracised Bahai minority, in its northwest region hit by deadly quakes last month, news agencies Tuesday quoted the country's prosecutor as saying.

Asked about rumours of arrests of 20 to 26 people, including some belonging to the Bahai faith, Gholam Hossein Mohseni Ejei confirmed to several news agencies that "more than 20" people had been apprehended.

"These people were carrying out disruptive acts, and not all of them are still under arrest and some are free. And 20 cases have been sent to prosecutors and they are being investigated," he was quoted as saying by the ISNA news agency.

Mohseni Ejei did not give details of the charges against the suspects, nor what acts they were accused of committing.

He appeared implicitly to confirm that Bahais were among those arrested. On the website of state broadcaster IRIB he was quoted saying: "Of course no one gets arrested just for being Bahai."

The Bahai faith was created in Iran two centuries ago and has faced severe repression both before and after the 1979 Islamic revolution.

Bahais consider Bahaullah, born in 1817, to be the latest prophet sent by God, a major divergence from Islamic orthodoxy. They call for unity of all religions and equality between men and women. There are estimated to be seven million in the world, 300,000 of them in Iran.

Iran's authorities consider the Bahais to be heretics, and often accuse them of being Israeli spies because their historic world headquarters is located in Haifa, in modern-day Israel.

The Bahais are barred from pursuing higher education in Iran, where several dozen of their leaders are imprisoned.

The double earthquakes of August 11 in northwest Iran, near the city of Tabriz, killed more than 300 people and injured 3,000, according to the official toll.

Thousands of Iranians mobilised to help the quake survivors, some of them operating outside of official channels they viewed with suspicion to deliver aid directly to the disaster zone.

Some of these independent relief operations were stopped by Iranian police or intelligence officials, according to opposition websites.