STRASBOURG, June 25 (RIA Novosti) - The Parliamentary Assembly of the Council of Europe on Thursday expressed concern over the clampdown on street protests in Iran following the controversial reelection of President Mahmoud Ahmadinejad last week.

Ahmadinejad's landslide victory on June 12 sparked mass protests amid opposition allegations of ballot fraud. At least 13 people are reported to have been killed according to Iranian media and over 450 arrested in the largest challenge to the Islamic Revolution since the 1979 overthrow of U.S.-backed Shah Reza Pahlavi.

Despite calls by some western powers, Iranian state television reported on Tuesday that the Guardian Council would not annul the results of the presidential vote.

PACE called the protests and demonstrations a lawful political action and said on its website: "The only way to find a peaceful and sustainable solution to the present situation in Iran, as well as stability and peace in the region, is through democracy, respect of human rights and the rule of law."

PACE said it is ready to make all necessary efforts to "initiate a meaningful dialogue" between the international community and Iran's parliament and democratic forces.