Jail sentences against seven other activists, ranging from two to 15 years and including Sunni opposition leader Ibrahim Sharif, were also upheld by the national safety appeals court, it said, quoting military general prosecutor Colonel Yusof Fulaifel.
Seven others, one sentenced to life in jail and the remainder to 15 years, remained at large and had not appealed against their sentences.
The appealed verdicts will go to a civil court of cassation for a final decision.
The eight activists sentenced to life include Hassan Mashaima, head of the Shia opposition Haq movement, Abdulwahab Hussein, who leads the Shia Wafa Islamic Movement, and Shia human rights activist Abdulhadi al-Khawaja, who is also a Danish citizen.
Activist and Haq member Abduljalil al-Singace, who was released in February after six months in jail, was also sentenced to life.
The other four are Mohamed Habib al-Muqdad, who holds a Swedish passport; his cousin Abduljalil al-Muqdad and Saeed Mirza, both of whom are Wafa members, and Said Abdulnabi Shihab, who was sentenced in absentia.
Sharif, the Sunni leader of the Waed secular group, who played a prominent role in month-long protests for democratic reform that were crushed in March, received a five-year sentence.
He and other leading opposition figures were arrested amid the crackdown on the protests which were led by the islands’ Shia majority.
Nine of the defendants had been in custody on similar charges in the past before being set free under a royal pardon in February aimed at calming the protests.
The Paris-based International Federation of Human Rights condemned the court’s ruling.
“We deeply regret the judgements,” Khadija Sharif, the organisation’s assistant secretary general, said after the rulings were handed down yesterday.
Sharif said the convictions were “arbitrary” and “inequitable” and called on the Bahraini courts to release the prisoners.
Scores more activists are facing trial on charges linked to the protests in a semi-martial court set up under a “state of national safety” decreed by King Hamad a day before protesters were evicted from a Manama square in mid-March.
Authorities backed by troops that rolled into Bahrain from fellow Gulf nations quelled the protests while security forces set about arresting hundreds of activists, as well as doctors, medics and teachers accused of backing protesters.
Bahrain’s interior ministry said 24 people, including four policemen, were killed in the unrest. The opposition puts the death toll at 30.
Yesterday, Iranian lawmakers criticised Saudi Arabia’s “role” in suppressing the protests in Bahrain and Yemen, and called on the UN to send a delegation to investigate the human rights situation in both countries.
The statement, posted on the Iranian parliament’s website, was signed by 210 MPs of the 290-seat parliament.
“The killing of innocent people in these two countries, in light of Saudi Arabia’s role, shows the weakness of the governments,” in Manama and Sanaa, said the statement.
The statement called on the UN to send a delegation to investigate the human rights situation and to “stop Saudi Arabia’s interference in the internal affairs” of the two countries.
The lawmakers also denounced “the West’s silence” in the face of “savage suppression.”
Iran has vocally supported most uprisings in the Arab world, with the exception of the revolt in its regional ally Syria, where it backs the regime of President Bashar al-Assad while advocating reforms.
Tension between Iran and Saudi Arabia rose sharply in March when Saudi troops intervened to help Bahrain suppress the protests.
