A girl in a short white manto whose long hair was tumbling out the front of her headscarf is taken by the police to one of the minibuses on Vanak Square in central Tehran — an unexpected and unhappy end to her shopping trip.

Another arrested woman is already inside the bus. She begins to cry. "I promise, I promise!"

And the minibus doors slam shut.

Tehran's police have said they are operating a three stage process in implementing the new wave of a crackdown on dress deemed to be unIslamic, which started with some intensity on Monday afternoon.

First, women are given a verbal warning on the street. If the problem is not resolved there, they are taken to the police station for "guidance" and to sign a vow not to repeat the offence. Should this be unsuccessful, their case is handed to the judiciary.

Just before the new crackdown started, popular television host Farzad Hasani grilled Tehran's police chief Ahmad Reza Radan about the drive on his talk show, accusing the police of "not differentiating between people and thugs."

An old woman in a black chador in Vanak Qquare echoed the sentiment.

"Our youth have no peace of mind. They are afraid to go out, they are afraid that if they go out they will be taken to the police. Aren't they saying that there is freedom?"

Authorities announced new arrests in the cases of two Iranian-Americans held on charges of conspiring against the government, saying Wednesday that an unspecified number of Iranians had been detained.

State radio quoted Intelligence Minister Gholam Hossein Ejehei as saying that: "Internal elements related to these people have been arrested."