A Bahraini court sentenced 22 Shias to 15 years in prison Wednesday over the killing of a policeman and wounding another in an attack outside Manama, a judicial source said.
Another defendant was jailed for only three years because he is a minor, while two others were acquitted.
The 25 were accused of involvement with a bomb that targeted police in the Shia village of Akr, and of attacking security forces with iron rods and petrol bombs, BNA state news agency said.
The policeman died of wounds after an iron rod penetrated his skull, BNA said citing a prosecution statement.
Sixteen of the defendants remain at large, it said.
Since the 2011 Shia-led uprising, which called for democratic reforms, demonstrations have regularly been held in villages around the capital, often sparking clashes with security forces.
At least 89 people have been killed in the Sunni-ruled kingdom since the protests began, according to the International Federation for Human Rights.
Several bomb attacks have taken place in recent months, including one that targeted a Sunni mosque close to the royal court in July but caused no casualties.