Some more detail of what the opposition says happened today:
at one of the several opposition rallies around the city, a group of hard-liners pushed through the crowd and attacked former President Mohamad Khatami, a cleric who is one of the most prominent pro-reform figures, according to a reformist Web site. The report cited witnesses as saying the opposition activists rescued Khatami and quickly repelled the assailants.
Another reformist Webs site said Khatami's turban was disheveled and he was forced to leave the march.
Hard-liners tried to attack the main opposition leader, Mir Hossein Mousavi, when he joined another protest elsewhere in the city, a witness said.
Supporters rushed Mousavi into his car when the hard-liners approached, and the vehicle sped away as his supporters pushed the hard-liners back, the witness said. He and other witnesses spoke on condition of anonymity for fear of government retaliation.
In one of the main Tehran squares, Haft-e Tir, baton-toting security forces tried to break up one of the opposition marched, and were met with protesters throwing stones and bricks, witnesses said. Several policemen were seen being taken away with light injuries. At least 10 protesters were seized by plainclothes security agents in marches around the city, witnesses said.