Bahrain Mirror (AFP): A bomb attack targeted a police station in a Bahraini Shiite village without causing casualties, the Sunni-ruled kingdom's official BNA news agency reported Friday.

Bahrain has been the scene of frequent unrest since a Shiite-led uprising in 2011 to demand a constitutional monarchy and an elected prime minister.

The Gulf state's deputy chief of public security, Major General Naji Al-Hajil, said the attack took place late Thursday in Bilad Al-Qadeem village.

"An investigation has been launched to identify the suspects and bring them to justice," said Hajil, quoted by BNA.

Protesters often clash with police in Shiite villages across Bahrain, which has accused Tehran of backing the unrest.

Bahrain's main Shiite opposition bloc, Al-Wefaq, condemned Thursday's "incident."

"These violent acts are isolated from the wide peaceful movement for legitimate rights. Any harm to lives or properties is strongly condemned," it said in a statement.

At least 89 people have been killed in clashes with security forces over the past four years, while hundreds have been arrested and put on trial, rights groups say.