The Associated Press reports:
Tens of thousands of supporters of pro-reform leader Mir Hossein Mousavi are streaming through the center of Tehran in a boisterous protest against election results that declared President Mamoud Ahmadinejad the winner.
The crowd - many wearing the trademark green color of Mousavi's campaign - was headed toward the capital's huge Freedom Square in the largest display of opposition unity since Friday's elections ended with Mousavi claiming widespread fraud.
There was no sign of violence or challenges from security forces. Anti-riot stood by with their helmets off and shields at their sides.
