Bahrain's appeals court postponed on Tuesday its verdict in the case of 13 leading opposition figures facing jail sentences over charges of plotting to overthrow the Gulf monarchy, lawyers said.
The defendants who played leading roles in the month-long protests last year demanding drastic democratic reforms did not turn up in court, lawyers said, adding that the court set September 4 as a new date for its verdict.
Amnesty International criticised the decision saying the opposition leaders, whom it describes as "prisoners of conscience", should be released and their convictions quashed.
"The defendants have endured months in detention already," Hassiba Hadj Sahraoui, Amnesty's deputy director for the Middle East and North Africa Programme, said in a statement.
"But instead of quashing their convictions and releasing them, the Bahraini authorities have resorted to the now-familiar tactic of postponing the hearing and toying with defendants, thus prolonging their ordeal and that of their families," she added.
The watchdog also quoted Ghanim Alnajjar, an internationally recognised human rights expert who observed the court proceedings on behalf of Amnesty, as saying: "The decision to postpone the final verdict is unjustified, and is tantamount to a denial of justice."
The 13 activists are being retried in a civil court after they were convicted, along with seven others who remain at large, of plotting to topple the Sunni ruling family.
Another defendant was acquitted.
The prosecution has dropped charges "related to the freedom of expression," for saying things that were considered illegal in the past.
On trial is activist Abdulhadi Khawaja who ended in June a 110-day hunger strike.
Also on trial Hasan Musheime and Abdel Jalil al-Sankis, both leaders of the Shiite Haq banned movement, as well as Sunni leftist Ibrahim Sharif, who heads the secular Waed group.
In June last year, a specially formed tribunal handed down lengthy jail terms against the 21 mostly Shiite activists after convicting them of plotting to overthrow the regime.
Ten months later, Bahrain's highest appeals court ordered a retrial.
Bahrain came under strong criticism from international human rights organisations over last year's crackdown on the Shiite-led protests.
An international panel commissioned by King Hamad to probe the government's clampdown found out that excessive force and torture had been used against protesters and detainees.