Bahrain has experienced unrest over past three years by majority Shi'ite Muslims
A blast caused by a homemade bomb on a highway west of Bahrain's capital Manama caused minor injuries to several policemen, the Gulf Arab kingdom's Interior Ministry said on Tuesday.
Bahrain has experienced unrest over the past three years by majority Shi'ite Muslims demanding political reform and an end to what they see as sectarian discrimination, something the government denies.
As well as regular protests, there have been attacks on security forces using homemade bombs. A bomb attack on March 3 killed three policemen and another on March 11 injured two.
Bahrain is closely watched by Western countries because it is home to the U.S. Fifth Fleet and has become a frontline in regional tensions between Shi'ite Iran and Sunni Saudi Arabia.
Bahrain has accused Iran of fomenting unrest in the kingdom. Iran denies having links to Bahrain's opposition or any hand in the violence, but it champions the cause of Shi'ites there.