DUBAI (Reuters) - Bahrain's highest court upheld on Monday the prison sentences of 13 leaders of a 2011 uprising, a defense lawyer said, in a ruling that could stir further unrest in the U.S.-allied Gulf Arab state.
The case has drawn international criticism from rights groups and come under scrutiny from U.S. officials keen for acquittals to help restore calm in a country that it counts as a regional partner against Iran.
Bahrain, where the U.S. Fifth Fleet is based, has been in political turmoil since a protest movement led by majority Shi'ite Muslims erupted in February 2011 during a tide of revolts against governments across the Arab world. Bahrain accuses Shi'ite power Iran of encouraging the unrest.
The sentences handed down by a military court in June 2011 and upheld by a civilian court in September last year range from five years in prison to life.
"This verdict is final. No more appeals are possible. It is the last stage of litigation," lawyer Mohammed al-Jishi told Reuters by telephone from Manama.
Twenty uprising leaders had been sentenced but only 13 filed appeals. The remaining seven men were tried in absentia because they were out of the country or in hiding, Jishi said.
The main charges the convicted men faced were "forming a terrorist group with intent to overthrow the system of government", as well as collaboration with a foreign state.
The men denied all the charges, saying they wanted only democratic reform.
In September, a prosecution official accused six of the convicted men of having "intelligence contact" with Iran and its Lebanese Shi'ite militant ally Hezbollah.
Bahrain's main opposition group, Al Wefaq, condemned Monday's decision. "These judgments confirmed the rulings issued before by the military court which were condemned by the whole world. I think it is accurate to call these rulings political persecution," Wefaq leader Sheikh Ali Salman told Reuters.
The U.S. government criticized the ruling.
"We regret today's decision," State Department spokeswoman Victoria Nuland told reporters in Washington. "We're concerned that this decision further restricts freedom of expression and compromises the atmosphere within Bahrain for reconciliation."
"We call on the government of Bahrain to investigate all reports of torture, including those made by the defendants in this case, as it has pledged to do, and to hold accountable any who are found responsible," she added.
Britain, another Western ally of Bahrain, said it was "deeply dismayed".
"At the time these individuals were sentenced, reports which were acknowledged by the Bahrain Independent Commission of Inquiry suggested that some had been abused in detention, denied access to legal counsel and were coerced into confessing," Middle East Minister Alistair Burt said in a statement.
"I call on the government of Bahrain to meet all its human rights obligations and guarantee its citizens the fundamental liberties to which they are entitled."
The men who received life sentences - 25 years in Bahrain - included rights activist Abdulhadi al-Khawaja and Hassan Mushaimaa, an opposition leader who has advocated turning the kingdom of Bahrain into a republic.
Ibrahim Sharif, leader of the opposition Waad party and the only Sunni among those convicted, is serving a five-year sentence.
The hearing was attended by a number of foreign diplomats, Jishi said.
Several protesters gathered in front of the court on Monday in support of the uprising leaders, Wefaq said via Twitter.
The ruling Sunni Muslim Al Khalifa family, backed by troops from Saudi Arabia and police from the United Arab Emirates, put down the uprising with martial law. Thousands were arrested and military trials were conducted.
Washington has called on its ally to talk to the opposition, but unrest has continued. Police and demonstrators clash almost daily and each side blames the other for the violence.
The protest leaders are viewed by some Bahrainis as popular heroes whose release could reinvigorate the democracy movement, which wants a parliament with the power to legislate and form governments. Bahraini Shi'ites say they are discriminated against in many aspects of life, a charge the government denies.
Additional reporting by Mohammed Abbas in London and Arshad Mohammed in Washington; Editing by Sami Aboudi, Tom Pfeiffer and Paul Simao