Media advocacy group Reporters Without Borders said Thursday that Iranian authorities arrested, jailed and sometimes executed 1.7 million people around the capital Tehran alone in the first 30 years after the 1979 Islamic revolution.

The organization revealed its count that included regime opponents, Baha'is and other religious minorities and at least 860 journalists.

The group said at a news conference that its information was based on a confidential file of judicial proceedings obtained by whistleblowers.