The ruling could further destabilize the Western-allied kingdom, where sporadic protests have erupted and occasional bomb attacks have taken place since the government quelled mass protests in 2011 led by Shi’ite Muslims demanding reforms.
The verdict was announced by the chief prosecutor of terrorist crimes who said that the three were among 12 people charged with a bomb attack in February that killed the policeman Abdel-Wahed Sayed Mohammed Faqeer in the village of al-Dair, north of the capital Manama.
The court sentenced the remaining nine suspects to six years in jail and fined them 1,000 Bahraini Dinars ($2,652) each, according the official Twitter account of Bahrain’s Public Prosecution.
The court ruling, which is subject to appeal, is only the fourth time in over 34 years that death sentences have been passed on Bahraini citizens.
It came a day after authorities detained Sheikh Ali Salman, head of the main Shi’ite Muslim opposition group al-Wefaq, who led a rally last week to denounce Bahrain’s November elections which were boycotted by the opposition.
In apparent reference to Sheikh Salman’s detention, Shi’ite regional power Iran said on Monday that intensified security measures would further complicate matters in Bahrain, where the Shi’ite majority demands greater social, political and economic equality with the ruling Sunni minority.
"Instead of resorting to worn out tactics, the authorities in Bahrain should initiate trust and pave the way for serious dialogue between the people and the rulers," Iran’s Foreign ministry spokeswoman Marzieh Afkham was quoted as saying by the state news agency IRNA.
Bahrain, where the U.S. Fifth Fleet is based, has accused Iran of fomenting unrest in the country, a charge Tehran denies.