Bahrain rounded up dissidents Thursday as it came under mounting diplomatic pressure to end a bloody crackdown on Shiite-led protesters which has alarmed its ally the United States and infuriated Iran.
Five hardline Shiite activists and one Sunni were rounded up during the night, a parliamentarian from the Shiite opposition alliance said, after a day of violence which left five dead in the Sunni-ruled kingdom.
"They were arrested in the night," Khalil Marzouk, deputy leader of the Al-Wefaq opposition movement, told AFP.
Among those arrested was Hassan Mashaima, a leader of the hardline Shiite Haq group which is seeking to overthrow the Sunni monarchy that has ruled the Shiite-majority island state for 230 years.
Radical Shiite elements like Haq want a republic.
Human rights activist and Haq member Abduljalil al-Singace, who was released in February after six months in jail, was also detained, the opposition said.
The government has not confirmed the arrests.
Security forces firing tear gas and shotguns cleared out a month-old pro-democracy sit-in at Manama's Pearl Square on Wednesday in the worst day of violence since activists took to the streets last month.
The opposition said three demonstrators were killed in the raid, while the government said two police died in hit-and-run attacks by opposition motorists.
US President Barack Obama, whose country is a close ally of Bahrain, called King Hamad to express "deep concern," while British Prime Minister David Cameron urged the king to pursue "reform, not repression."