|At least 40 people have been killed in crackdowns on protesters demanding change in the Sunni monarchy [Reuters]
Security forces firing rubber bullets and tear gas have attacked the headquarters of Bahrain's main Shia opposition party in the capital Manama.
Police also used tear gas to disperse hundreds of opposition supporters attempting to protest elsewhere in the capital.
A 13-year-old girl was among those hurt, with a serious injury to her thigh, opposition officials said.
Friday's clampdown was the latest episode in 10 months of unrest between Bahrain's Sunni monarchy and an opposition movement led by the country's majority Shias, who have long complained of discrimination.
Matar Matar, a fromer al-Wefaq member of parliament, said they had given the government a proper notice regarding the protest, but police still used excessive force to disperse their supporters.
“Today, the government did not allow us to do our protest. Even the legal protests are facing difficulty and the space is reducing for the freedom of expression,” he told Al Jazeera.
“We were expecting the opposite after the BICI [Bahrain Independent Commission of Inquiry] report; that there would be more space.”
The report, released last month, said security forces used excessive force and tortured detainees during its crackdown.
King Hamad bin Isa al-Khalifa pledged that officials involved in the abuses would be held accountable.
“We are asking the government to enter a partnership and dialogue to implement the recommendations of BICI, but the response was just the opposite,” Matar said.
“They are trying to marginalize us, and trying to ignore all our calls for partnership and negotiations.”
Defying government orders, Shia clerics on Friday also held prayer services on the rubble of mosques that had been bulldozed by authorities earlier this year.
It was the first time that Shia clerics have actively taken part in the protest movement, openly defying the government.
Clerics say at least 38 mosques used by their congregations were destroyed since the protests began in February.
"We will start a campaign to defend our religious sites and the first such activity starts with a protest at the end of the prayer at Diraz grand mosque,'' said Sheikh Isa Qassim, a senior Shia cleric, during his Friday sermon.
Diraz is an opposition stronghold northwest of the capital.
"We demand democracy for one people, Sunni and Shia, and we understand the approach of the government that aims to divide our people. We are the ones who insist on unity, and because of this we are targeted by the government,'' he said.
Since February, at least 40 people have been killed in crackdowns on protesters. Hundreds of activists have also been detained and brought to trial on anti-state charges in a special security court set up after authorities imposed marital law and invited a Saudi-led Gulf military force into the country to help deal with dissent.