At least one person has been killed and another injured in the second bomb blast in Bahrain within 24 hours, according to interior ministry officials.
The latest attack in a predominantly Shia village southeast of the capital, Manama, on Tuesday came after a policeman was killed on Monday night in what officials called a "terrorist" attack, which they blamed on the Lebanese group Hezbollah.
The fresh explosion in Karzakan killed a Bahraini national and slightly wounded an Asian national, the interior ministry said.
Monday's bomb attack killed an officer "while on duty" in the predominantly Shia town of Damistan, prompting police to cordon off the village and tightened security checks amid a probe into the attack.
Political tensions have been running high in Bahrain since the opposition boycotted elections last month.
The island kingdom, which is home to the US Fifth Fleet, was swept by unrest during the 2011 Arab uprisings when the majority Shia demanded political reforms.
Gulf leaders meeting in the Qatari capital Doha on Tuesday are expected to discuss security issues in a region badly shaken by sectarian bloodshed, though the Sunni Gulf monarchies have been largely spared.