A special court in Bahrain has upheld life sentences for eight Shi'ite opposition activists convicted of plotting to overthrow the minority Sunni-led government during anti-government protests earlier this year.

The state-run Bahrain News Agency said the court confirmed the sentences Wednesday, along with those of 13 other activists who received prison sentences ranging from two years to 15 years on similar charges of sedition.

Amnesty International criticized the court's decision, saying it showed the “inherent unfairness” of Bahrain's trial process. The rights group said the decision shows that Bahrain has “no intention of meeting international fair trial standards” for those perceived as political opponents.

All of the defendants can appeal their sentence to a higher court.

Bahrain received help from some of its Gulf Arab neighbors to quell the anti-government protests that began in February. About 40 people were killed during clashes between security forces and protesters. More than 1,000 people were detained.

The government has defended the crackdown, saying it was needed to reinstate stability.