Bahrain’s high criminal court sentenced 12 Shiites to 10 year in prison for attempting to kill policeman in the Shiite-village of Sitra, Bahrain’s state news agency BNA reported said on Sunday.

Another defendant was handed down a three-year prison sentence and four more were acquitted.

The seventeen Shiite defendants were arrested in May 2012 over charges of attempting to murder police, perpetrating arson attacks on police vehicles, causing public disturbances, possessing Molotov cocktails and joining an organization “that uses terrorism as means to achieve its aims,” Bahrain National TV said.

According to the Bahrain Human Rights Watch Society, many Shiites have been sentenced to prison in Bahrain, following King Hamad’s announcement in August, 2013 calling for harsher penalties for those committing “terror acts.”

In a separate case, a policeman was acquitted for attempting to murder a protest due to insufficient proof, a judicial source stated Sunday, BNA reported.

The police officer was originally charged in April 2012, when Saleh Abbas, a Shiite, was shot dead during a protest in Shakura.

Though he was acquitted for lack of evidence, the policeman did admit that he was the only member from the police patrol to open fire on the day of Abbas’ killing, during his cross-examination in court.

Meanwhile, Bahrain’s Interior Ministry on Saturday evening, announced it had arrested two Gulf Arab citizens suspected of plotting “terror” attacks against the Kingdom.

The two Gulf nationals reportedly tried to enter Bahrain using fake passport through the Kind Fahd causeway – which connects Bahrain to Saudi Arabia – and had a large amount of money in their possession, the ministry said late Saturday, according to Reuters.

“The initial investigation revealed that the arrestees are former detainees of the Guantanamo detention center. They are suspected of plotting a terror act to jeopardize the security and safety of Bahrain,” the ministry statement added.

The statement did not elaborate further on the nature of the planned attacks and did not shed further light on the identities of the Gulf nationals arrested, according to Reuters.

Bahrain, a staunch ally of the West and the home to the US Navy’s Fifth Fleet, has been rocked by political and social unrest since protests, led by the Shiite majority, broke out in February 2011.

According to media outlet, the two and half years of violent demonstrations in Bahrain, acts of sabotage and repression, have left 89 people dead including police officials and injured hundreds others, according to the International Federation of Human Rights. Many Shiite activists have been arrested and are on trial for their roles in the unrest, according to the Bahrain Human Rights Watch Society.

Bahraini authorities always accuse Tehran and Hezbollah of being behind troubles in the country, where a Sunni ruling family governs a mainly Shiite population.

Meanwhile, Iran rejected Bahraini allegation of being encouraging anti-government protests and called on Bahraini officials to address demands of their people, instead of putting the blame on others.