A reliable twitterer tweets:
Clashes in Behesht Zahara, Karoubi entred.
Clashes at Ferdosi Sq. (not Conf), Army Helicopters flying over Central City.
R Police Returned Mousavi from Behesht Zahra, no news from Karoubi, more ppl are trying to enter where Neda is buried.
Protesters gatherd in Seyde Khandan, Hafte Tir , Vanak and Vali Asr Cr.
+10,000 gatherd in Behesht Zahara under heavy sec cont more ppl re expecting join for Memorial of 20 June Uprising victims
Reuters reports the basic narrative:
Iranian police arrested mourners who gathered at a Tehran cemetery to commemorate victims of the unrest that followed the country's disputed June presidential election, witnesses said. "Hundreds have gathered around Neda Agha-Soltan's grave to mourn her death and other victims' death ... police arrested some of them ... dozens of riot police also arrived and are trying to disperse the crowd," a witness told Reuters.
Iranian police forced opposition leader Mirhossein Mousavi to leave [the cemetery]."Police forced Mousavi to return to his car and leave the cemetery. Police are also warning mourners to leave the place or face the consequences," a witness told Reuters.