Bahraini police fired tear gas to disperse protesters who took to the streets Saturday on the fourth anniversary of a pro-democracy uprising.
Police deployed heavily as men and women carrying Bahrain's red and white flag alongside portraits of detained activists chanted "Down Hamad" in reference to the king, witnesses said, AFP reported.
They fired tear gas and sound bombs and beefed up security around several villages and along major roads across the country, the witnesses said.
Amnesty International urged Bahrain to "rein in" its security forces and "seize the opportunity of the fourth anniversary of the uprising to announce genuine and long overdue reforms."
The opposition said on Twitter that the police fired buckshot, and posted pictures of wounded protesters. It also said several activists were arrested.
The security measures were aimed at preventing the demonstrators from advancing towards the center of the capital Manama, where the 2011 uprising was focused.
Protesters burned tires and used rocks, garbage containers and branches to block roads in the villages.
The February 14 Coalition, a cyber youth group, had urged demonstrations and strikes across the Arab state under the slogan "Strike of Defiance."
However, the public security chief, Major-General Tariq al-Hassan, had issued a stern warning ahead of the protests. "Action will be taken against those who spread terror among citizens or residents, put the safety of others at risk or try to disrupt the nation's security and stability."
Bahrain's regime crushed protests led by its majority Shiites shortly after they erupted on Feb. 14, 2011. Home to the US Fifth Fleet, Bahrain is one of several Arab states that backs US-led airstrikes against IS in Iraq and Syria, making it a vital Western ally.
Tensions are running high in the kingdom where a sectarian divide is deepening and there is a growing gap between the Sunni government and its mainly Shiite opponents.
Opposition leader Sheikh Ali Salman is behind bars for allegedly trying to overthrow the regime. His arrest on Dec. 28, shortly after he was re-elected head of Bahrain's main opposition party Al-Wefaq, has sparked massive protests across the country.
