Iran’s main opposition leaders Mir Hossein Mousavi and Mehdi Karroubi have been arrested, according to the Kaleme website, which is close to Mousavi. The two are said to have been transferred to the Heshmatiyeh Prison in Tehran. The website says their wives have also been taken.

Kaleme cited “reliable sources” for its report. No information has been given on when the arrests took place.

The leaders have been under house arrest for weeks. They were candidates in the June 2009 presidential elections in which the incumbent Mahmoud Ahmadinejad won, drawing criticism that the vote was rigged. Ahmadinejad and his supporters denied fraud.

Mousavi was Iran’s premier for eight years in the 1980s, while Karroubi has been a speaker of parliament.