Two attacks in Shia-majority villages in the Gulf state of Bahrain have left one police officer dead and at least three others injured, officials say.A bomb exploded at the police station in Sitra, killing one officer, while three police were injured in a petrol bomb attack in Janabiya.
More than 60 people have died since pro-democracy protests broke out in the island kingdom in February 2011.
Bahrain's ruling family is Sunni Muslim but most of the population are Shia.
Sitra, not far from the capital Manama, has been the scene of previous clashes between police and anti-government protesters.
A statement from the Bahrain News Agency, quoted by the AFP news agency, said two police officers had also been injured there.
In Janabiya, three police officers were hurt when their patrol was attacked with petrol bombs, the interior ministry said.
Later, the Interior Ministry said three policemen were injured when their patrol was hit by firebombs in another area of the strategic kingdom, which is home to the US Navy's 5th Fleet.
Youths armed with petrol bombs attack police on an almost nightly basis in villages and towns around the capital.
The police respond with teargas, stun grenades and birdshot but are frequently accused by the opposition of using excessive force against protesters.
The opposition says that helps fuel an ongoing cycle of violence.