There are reports of violence during a protest in Teheran against the recent murders of several Iranian dissidents and intellectuals.

A witness, speaking to the BBC, said the protestors were attacked by a group of thugs wielding clubs.

According to one account, the police moved in to halt the violence, but another report said that they failed to intervene.

In a separate development, President Mohammad Khatami has called for a speeding-up of the investigation into the killing of the dissidents.