A fresh wave of clashes broke out Friday in Bahrain between pro-reform demonstrators and police, dpa reported.
In Manama, police fired several rounds of tear gas at the headquarters of the leading Shiite opposition group, al-Wefaq, while several of al-Wefaq members and pro-reform demonstrators were taking shelter inside.
The incident occurred in the wake of clashes outside the building, as protesters tried to march on Tubli Bay in the capital to hold a sit-in, which was called by the opposition and banned by police.
Seyyed Hadi al-Mosawi, a former parliament member for al-Wefaq, was fired on with tear gas and sound grenades by anti-riot police, as he joined a group of protesters trying to break past the protest site, which police had sealed off.
The unrest quickly spread from Manama to other parts of Bahrain, with some of the worst incidents being reported in Sitra, on the western part of the island, where hundreds clashed with police.
Youtube video posted by activists on the internet showed anti-riot police hurling Molotov cocktails at protesters in Sitra.
Other Youtube video showed protesters hurling firebombs at police who were trying to advance into their villages while firing tear gas.
According to the activists, more than 60 locations had witnessed unrest since late Thursday, with photos and video surfacing since then, showing families including children either taking shelter in their homes or fleeing houses that had been hit with tear gas.
Bahrain, home of the US Navy's Fifth Fleet command, has been rocked by pro-reform protests since mid-February.
More then 40 people have been killed, hundreds injured and unspecified numbers imprisoned.
Thousands have been sacked from their jobs for supporting the protests, following a crackdown in mid-March.
Earlier this month, Michael Posner, the US assistant secretary of state for democracy, human rights and labor, who was on a visit to Bahrain, called on all parties to refrain from violence. He expressed concern over reports of excessive force by security forces against protesters.
UN human rights chief Navi Pillay called Wednesday on Bahraini authorities to address the "deepening mistrust" between the government and civil society. He urged the unconditional release of people detained for participating in peaceful protests.