A Bahrain court on Tuesday upheld jail terms against 13 leading opposition figures, including seven facing life in prison, over charges of plotting to overthrow the Gulf monarchy, lawyers said.
The opposition swiftly condemned the "vindictive" rulings and accused the court of staging "mock trials," the United States expressed its concern, while London-based Amnesty International denounced the ruling as "outrageous."
The defendants, who played leading roles in month-long protests last year demanding democratic reforms, did not turn up in the appeals court, the lawyers said.
The 13 activists were being retried in a civil court after they were convicted by a special semi-military court, along with seven others who remain at large, of plotting to topple the Sunni ruling family.
Another defendant was acquitted.
The prosecution had dropped charges against all defendants "related to the freedom of expression" which were considered illegal by the National Safety Court set up to try people who took part in the uprising.
Among those sentenced is activist Abdulhadi Khawaja who in June ended a 110-day hunger strike.
Also sentenced were Hasan Musheime and Abdel Jalil al-Sankis, both leaders of the banned Shiite movement, Haq, as well as Sunni leftist Ibrahim Sharif, who heads the secular Waed group.
"Today's ruling is a clear proof of the fake justice in Bahrain," said the main opposition groups in a statement.
"Those are politically motivated verdicts that have no judicial value, because they have been based on a vindictive methodology," they said.
"There is no state in Bahrain. It is a tyrannical authority, and an oppressive government that tries to look like a (political) system while hiding security apparatuses that terrorise the people to silence its demands for democracy."
The main Shiite formation, Al-Wefaq, said it was a "black day for justice in Bahrain."
Signup to our newsletter and follow us on Facebook and Twitter!
"Those wrongful rulings will only strengthen the determination of the people to continue their revolution to the end," the group's leader, Ali Salman, wrote on his Twitter page.
In Washington, US State Department spokesman Patrick Ventrell urged Bahrain to keep to its commitment to respect the rights of detainees to a fair trial and access to attorneys.
"It is important that verdicts are based on credible evidence and that judicial proceedings are conducted in full accordance with Bahraini law and Bahrain's international legal obligations," he said in a statement.
"We call on the government of Bahrain to investigate all reports of torture, including those made by the defendants, as it has pledged to do, and to hold accountable those found responsible."
Amnesty lashed out at the verdicts, saying they must be "overturned and the activists immediately and unconditionally released."
"Today's court decision is another blow to justice and it shows once more that the Bahraini authorities are not on the path of reform but seem rather driven by vindictiveness", said Hassiba Hadj Sahraoui, deputy director of Amnesty's Middle East and North Africa Programme.
Sahraoui said Bahrain's human rights record will be up for scrutiny at the UN Human Rights Council in September.
In June last year, the 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.
The Sunni-ruled kingdom, home to the US Fifth Fleet and strategically situated across the Gulf from Iran, has continued to witness sporadic Shiite-led demonstrations, mostly outside the capital, since it crushed the protest movement in March last year.