Bahraini police dispersed protesters who made several attempts Tuesday to mark the anniversary of last year's uprising by marching to the site of the protest that was brutally crushed, witnesses said.
Several protests took off from Shia villages on the outskirts of Manama, with youth trying to reach the capital's former Pearl Square, where democracy demonstrators camped for a month last year before being forcefully driven out.
Protesters marched from Sanabis, Deih and Jidhafs, which lie few kilometres (miles) west of Manama, despite police warning that protests would be dispersed, witnesses said.
"Down with (King) Hamad!" they chanted, referring to the Sunni monarch whose Al-Khalifa has ruled the Shia-majority Gulf kingdom since the 18th century.
The Coalition of the Youth of February 14th Revolution, a hardline group that operates apart from the political opposition led by Al-Wefaq, declared Tuesday the day to return to the square that was razed after the mid-March crackdown.
"All of us are returning" to the square, read a call for protest posted on its Facebook page, designating 6:40am (0340 GMT) as the starting time.
The coalition posted footage of youth dressed in white Islamic death shrouds running through some alleys claiming they were heading to the square that is heavily protected by security forces.
It also posted a picture of women dressed in traditional black abayas (cloaks) standing close to the square flashing the victory sign.
On Tuesday, Al-Wefaq accused security forces of waging a campaign of arrests against people who took part in protests. It said 13 people were detained, including female activist Maasouma al-Sayyed, who is reported to have reached the square area.
It said police raided Shia villages where many houses were hit by tear gas canisters, and that several arrests took place overnight.
Activists have called for demonstrations on Monday and Tuesday at the square.
But the Al-Wefaq-led alliance of opposition groups said Monday following a large protest organised outside Manama that although Pearl Square has "become a symbol" for protest, it is not the only one, clearly distancing itself from the call to return.
"All squares and streets of the country are sites that we use to renew our vows to press ahead in our struggle to achieve our demands," including a powerful parliament, representative government and redrawn "fair" electoral constituencies, it said.
Bahraini security forces, boosted by Gulf troops that rolled in from neighbouring Saudi Arabia, quelled the month-long protest that appeared to take a cue from Arab Spring uprisings.
Human rights activist Nabeel Rajab, who has been holding daily protests in Manama with a group of activists, called for another march to Pearl Square.
"Let's drive at 3:30 pm (1230 GMT) towards the square, step out of cars and run to the (Pearl) roundabout," he wrote on his twitter account.
Leading Wefaq activist and former MP Matar Matar told AFP that security measures taken by authorities to prevent demonstrations amount to an "undeclared state of emergency."
King Hamad called for "cohesion" among Bahrainis in a statement released Monday to celebrate the 11th anniversary of the referendum on the charter that revived the parliament after it was dissolved in 1975.
"Lets begin a new phase of serious and sincere action aimed to achieve what is good for our homeland and its people," he said, as the Sunni-Shia rift has grown deeper in the tiny nation.
The death toll from last year's unrest was 35, including five security personnel and five detainees tortured to death while in custody, an international probe found last November.
But Amnesty International said "at least a further 20 have died since" in protests because of the continued use of excessive force by security personnel.