The explosion took place late yesterday west of the capital, Manama, in a predominantly Shiite village called Karanah.
The explosion, described by the ministry as a "terrorist blast," wounded four policemen as well as a married couple and their child. The statement did not disclose further details on the location or target of the explosion.
Last month, a bombing killed two police officers in Sitra, south of Manama. Police investigators say five suspects arrested for that attack are connected to Iran's Revolutionary Guard, as well as the Iranian-backed Lebanese Hezbollah group.
Bahrain hosts the US Navy's 5th Fleet.