Security forces in Bahrain have fired tear gas and stun grenades at protesters trying to occupy a landmark square in the nation\'s capital Manama. Monday\'s march by thousands of opposition supporters to Manama\'s Pearl Square was the largest attempt in months to retake the central roundabout that served as the epicenter of weeks of protests last year by Bahrain\'s Shiite majority against the ruling Sunni dynasty. The government deployed thousands of security forces to prevent the opposition from staging a mass rally to mark Tuesday\'s one-year of the revolt. Bahrain imposed martial law in March to quell the protests. Emergency rule was lifted in June, but clashes still occur on an almost daily basis. An independent commission later found the security forces guilty of abusing protesters and detainees.