Two people were killed Saturday when their car exploded in a Shiite village in Bahrain, the interior ministry said, although it was unclear whether the vehicle itself had been targeted.
A third person was wounded in the blast and taken to hospital as civil defence personnel were hurt in a separate explosion, the ministry said.
An uprising against the ruling Sunni dynasty in the Shiite majority kingdom began in 2011, and protesters still clash regularly with police.
"Two burned bodies and one injured person were found" in a "civilian" car that exploded in the Shiite village of Mughsha, the interior ministry said.
"Initial investigations have shown that the blast was caused by explosive devices inside the car," the official BNA news agency cited the ministry as saying.
No further details were given on whether the vehicle it had been targeted directly or whether the blast had been accidental.
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Witnesses said they heard a loud bang shortly before the car was gutted by fire, and that authorities cordoned off the area.
In another Shiite town, Al-Quraya, "a home-made bomb" exploded, wounding several members of the civil defence force "who were in the process of extinguishing burning tyres".
"Three civil defence members sustained multiple injuries and were admitted to hospital for treatment and several others were treated on site for minor injuries," an English-language statement said.
Witnesses in Al-Quraya told AFP that protesters against the ruling Al-Khalifa dynasty set tyres alight at the entrance to the village.
Bahrain remains deeply divided three years after the Shiite-led uprising, with persistent protests sparking clashes with police, scores of Shiites jailed on "terror" charges and reconciliation talks deadlocked.
Last year, the authorities increased the penalties for those convicted of violence, introducing the death penalty or life sentences in certain cases.
The International Federation for Human Rights says that at least 89 people have been killed in Bahrain since February 2011.