(CNN) -- Bahrain's highest court on Monday upheld the verdicts against 13 activists convicted of plotting to overthrow the government for their role in pro-democracy demonstrations sparked by the success of popular Arab Spring uprisings.
The country's highest appeals court took just minutes to rule on the appeal of the 13 people, who received sentences between five years and life, said attorney Mohsin Alawi, who represents three of the 13.
The ruling by the court was the last chance the 13 had to reverse their convictions. They were arrested for their roles in anti-government demonstrations in 2011 as the Arab Spring movement swept across the region.
Demonstrations in Bahrain failed to gain the traction of other Arab Spring uprisings after a crackdown by authorities, backed by troops from nearby Saudi Arabia and the United Arab Emirates.
In November 2011, Bahrain's Independent Commission of Inquiry issued a report critical of authorities' reactions to the protests, which began in February 2011, spurred by uprisings in Tunisia and Egypt.
Bahrain plays a key strategic role in the Middle East and is home to the U.S. Navy's Fifth Fleet headquarters.
When Bahrain's lower appeals court upheld the convictions in September, the U.S. State Department said it was "deeply troubled" by the convictions.
Amnesty International has called the convictions of the activists an outrage and urged Bahrain to overturn the sentences.
It slammed the decision Monday, saying it "is further proof of how the country's justice system simply cannot be relied on."
The government has defended its judicial procedures and decisions, saying it provided fair trials. It has pointed out that Amnesty International was one of the international entities that attended the trial.
Alawi's clients Abdul Jalil al-Mudad, Muhammed al-Muqdad and Abdul Wahhab Husain received life sentences, he said.