The Guardian, CNN and other media are reporting about sources inside Iran saying that some opposition leaders and their supporters have been attacked in Tehran by government forces today during pro- and anti-government demonstrations on the 31st anniversary of the Islamist revolution there.

The Associated Press reports that:

Authorities clamped down hard to prevent a major show of force by the opposition amid one of the country's most important political occasions. Tehran residents also reported Internet speeds dropping dramatically and e-mail services such as Gmail being blocked in a common government tactic to foil opposition attempts to organize.

As has been the case ever since last June's Iranian presidential election, one way to follow the news continues to be on Twitter via a search for #iranelection.