A car bomb exploded near a recreational area in Budaiya, west of the Bahraini capital Manama, on Saturday but no casualties were reported, the Interior Ministry said.
Two gas cylinders were planted in a parked vehicle but only one exploded, a ministry source told Reuters.
Bahrain, a majority Shi'ite country ruled by the Sunni al Khalifa family, has been buffeted by political unrest since 2011, with mostly Shi'ite Bahrainis agitating for democratic reforms and more say in government.
Authorities have crushed large-scale popular demonstrations on the island, which is home to the U.S. Fifth Fleet and sits between top oil exporter Saudi Arabia and Washington's main regional antagonist Iran, but small clashes and protests erupt almost daily.
A car exploded on July 17 outside a Sunni Muslim mosque in Riffa, south of the capital Manama, but no-one was hurt.
The main Shi'ite opposition party Al Wefaq condemned Saturday's attack.
"The Wefaq policy is based on peaceful methods," Al Wefaq official Khalil-al Marzouk said.
National reconciliation talks between the government and opposition parties have made little progress since they began in February.
Bahrain's lawmakers agreed last week to tougher penalties on what they called terrorist crimes and banned protests from taking place in the capital Manama ahead of planned mass demonstrations later this month.
Inspired by the "Tamarrod" (Rebel!) protests in Egypt which led to the military overthrow of Islamist President Mohamed Mursi in July, a protest movement in Bahrain called for demonstrations against the government on Aug. 14.
The Bahraini government has said anyone participating in the planned protests would "face the force of the law".