"It’s appalling what passes for ‘justice’ today in Bahrain," Amnesty International Middle East and North Africa director Philip Luther said on Monday.

The court sentenced the activists on Sunday, including a prominent Shia Iraqi cleric who was sentenced for forming a secret opposition group.

The activists were charged with allegedly organizing the ‘February 14 Revolution Youth Coalition’ and trying to topple the country’s constitutional monarchy by organizing bombings and inciting anti-government rallies.

The Persian Gulf kingdom equates the opposition group with "terrorism."

"The authorities simply slap the label ‘terrorist’ on defendants, and then subject them to all manner of violations to end up with a ‘confession,’” Luther said.

Twenty of the activists were reportedly convicted in absentia.

Sixteen of the activists received 15-year sentences, four were jailed for 10 years, and the other thirty received five-year terms.

Amnesty International stated that there are claims that some of the activists were tortured, and urged for a prompt investigation into the matter.

"The allegations that confessions were extracted under torture must be investigated promptly, thoroughly, and independently, with those responsible brought to justice," said Luther.

Earlier in September, Human Rights Watch accused the Bahraini government of violence and torture, with frequent reports of child protesters facing extremely harsh conditions while in custody.

The Persian Gulf state is a predominantly Shia country and has seen frequent unrest since authorities cracked down on the popular uprising against the ruling Sunni monarchy in 2011. Human rights organizations have condemned the West for turning a blind eye to the crackdown.

Bahrain, a small island nation and home to the US Fifth Fleet, has seen 80 people killed since the protests erupted, according to the International Federation for Human Rights. Hundreds more have been arrested.

NTJ/BA