This was written in a blog named "Kosoof " in Iran :

A group of about 130 women’s rights activists who gathered in Deneshjoo Park in central Tehran to celebrate International Women’s Day were brutally beaten by the police. As soon as the program started with distributing some brochures and chanting Iran’s women’s movement song, the police informed the attendants that their gathering is illegal and they should leave the premises. Then the police started beating men and women present in Daneshjoo Park and the program was ended. Simin Behbahani, the Iranian elderly famous poet was among the people who have been beaten.
According to Atricle 27 of Islamic Republic of Iran’s Constitution, public gatherings and marches may be freely held, provided arms are not carried and that they are not detrimental to the fundamental principles of Islam.

For music visit this link:
http://www.womeniniran.net/8march06/marsweb.htm
For more picture of the rally visit this link:
http://kosoof.com/