Amnesty International, a London-based human rights group, described the ruling as outrageous.
Bahrain, where the U.S. Fifth Fleet is based, has been in political turmoil since a protest movement dominated by majority Shi’ite Muslims erupted in February 2011 during a wave of revolts against authoritarian governments across the Arab world.
The Sunni Muslim ruling Al Khalifa family put down the uprising with martial law, troops from Saudi Arabia and police from the United Arab Emirates, but unrest has resumed, with almost daily clashes between Shi’ites and police.
The verdicts, originally issued by a military court against 21 men, including seven in absentia, include eight life sentences. Thirteen men remain in jail after one was released. Defense lawyers said Tuesday’s ruling could be appealed.
A prosecution official said six of the men were guilty of having “intelligence contact” with Iran and its Lebanese Shi’ite ally Hezbollah, seeking to overturn Bahrain’s system of government and violating the constitution.
“It is established clearly to us from this verdict that some of the accused had relations, and strived to have relations and intelligence contacts, with a foreign organization, Hezbollah, which works in the interests of Iran,” Wael Boualai told a news conference, according to state news agency BNA.
Hezbollah denies any involvement in the protests in Bahrain, but is critical of the government’s handling of the unrest.
The convicted men deny all charges, saying they wanted only democratic reform in the Gulf Arab monarchy. Seven were tried in absentia, having left the country or gone into hiding.
BNA said four were acquitted of charges of foreign intelligence communications and seeking to change and overthrow the system of government, but their sentences remained the same.
Mohammed al-Jishi, a defense lawyer at the hearing, told Reuters this was partly due to other charges that were not among a total of 12 declared on Tuesday by the judge or media. The other charges included insulting the army, inciting sectarian hatred and organizing protests without pe
Opposition activists fear Bahraini authorities want to prolong the case and hold onto the men as bargaining chips in an eventual resolution to the internal conflict. The government says courts in Bahrain are independent.
The authorities have initiated low-level talks with opposition groups, but said these groups must do more to stop street violence. The opposition says this stance is a ruse to avoid concessions and they are not responsible for clashes.
“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,” Amnesty’s Middle East and North Africa Deputy Director Hassiba Hadj Sahraoui said, calling the verdict “outrageous”.
The 20 men are viewed by some Bahrainis as popular heroes whose release could reinvigorate the protest movement, which demands parliamentary powers to legislate and form governments.
Bahraini Shi’ites say they face discrimination, a charge the government denies.
Jane Kinninmont, of London’s Chatham House, said the verdict sent a tough message to protesters as well as Western countries which have urged Manama to compromise with its opponents.
“The authorities may be trying to show their strength ahead of a planned dialogue with political societies,” she argued, saying this could backfire if protests and clashes escalate.
“This may also send a message to the international community about the limits of pressure. Strong Saudi backing for Bahrain has made it less interested in what the West has to say.”
Though U.S. officials are keen for a release of prisoners to help restore calm, Washington has avoided irritating Manama with public calls over the uprising leaders case.
The presence of U.S. warships helps ensure a free flow of oil exports from the Gulf, which Iran has threatened to blockade if the stand-off with Western powers over its nuclear energy program turns into military confrontation.
Danish Foreign Minister Villy Sovndal said the verdict was disappointing and called for the release of Abdulhadi al-Khawaja, a rights activist in the case with Danish nationality.
“It’s important that the international community continue to make Bahrain aware of the importance of the country respecting basic human rights,” Sovndal said in a written comment.
Eight of the 20 men received life sentences in a military court last year, including Khawaja and opposition leader Hassan Mushaimaa, who has advocated turning Bahrain into a republic.
Ibrahim Sharif, leader of the opposition Waad party and the only Sunni among the 20, is serving a five-year sentence while blogger Ali Abdulemam was given a 15-year term and is in hiding.
“I am very disappointed. This was a shock to people,” said Hussein Jawad, son of Mohammed Jawad, who is serving a 15-year sentence. “If they don’t want life or a future for Bahrain, they will keep the verdicts like this.”
Prosecutor Boualai said the men had been assured a fair trial, noting that they had a team of 17 defense lawyers and that foreign diplomats attended the reading of the verdicts.
But Jishi said the 13 in jail refused to attend in protest against the judge who had closed previous sessions to the public when the men testified that they were abused in detention last year to force confessions used in the military trial.
Some Sunni loyalists who fear the rise of Shi’ite Islamists in any government compromise with the opposition praised the ruling. “God is great, God is great,” wrote hardline cleric Mohammed Khalid on Twitter.