The first round of trials of opposition prisoners in Iran will begin this weekend.

The report said this was the "first phase" of trials, and that in later phases the defendants would be "those who ordered the post election unrest," an apparent reference to opposition politicians.

The conditions in the prisons are appalling. Many of the prisoners released yesterday have been reporting the abuses, sparking fresh outrage.

Accounts emerged from released prisoners about beatings and brutality during their detention. One told of being crammed with 200 other protesters in a pitch-black cell as guards waded in, beating them. Another said he and other detainees were forced to lick toilet bowls.

In recent days, there have been several deaths of young activists in prison — including the son of a prominent conservative. The announcement of trials is likely to anger the opposition, which says that detainees are being tortured into making false confessions to be used against them in court.

One told of being held at Kahrizak since his arrest in a July 9 protest, saying, "We were at least 200 people in one room, and everyone was getting beatings with sticks." He wrote that at one point the guards turned out the lights and beat the prisoners for a half hour. The protester, who said he was released on Monday, listed the names of six prisoners he believed had died during the assaults.