Mass demonstrations were staged in the Bahraini capital, Manama, and several towns and villages across the kingdom including Sitra, Belad al-Qadeem and Diraz on Friday on the eve of the anniversary of the revolution which started on February 14, 2011.
Police fired tear gas and rubber bullets to disperse protesters in Manama while clashes also broke out in several other towns.
Protesters, who are seeking a democratically-elected government, chanted slogans and called for the downfall of the Al Khalifa regime.
The demonstrators also urged the release of the main opposition leader, Sheikh Ali Salman, who has been under arrest since December last year on charges of inciting regime change.