Security forces in Bahrain have begun a pre-emptive crackdown ahead of nationwide anti-government protests scheduled for Wednesday.
The protests are being organised by a group calling itself "Tamarod," or "rebellion," mimicking the Egyptian movement of the same name, which organised protests that led to the military overthrow of president Mohamed Morsi last month.
The group has urged businesses to join them in a general strike, and plans to rally in Manama despite a recently-issued ban on protests in the capital and harsh new penalties aimed at curbing dissent.
Police on Tuesday set up checkpoints around Shia villages outside the capital which have been a main source of opposition to the government.
Sunnis are a minority of the population in Bahrain, but they have controlled the government for decades, and protests have largely been led by Shia activists alleging discrimination and economic inequality.
Al-Wefaq, the main opposition party in Bahrain, said that Sitra island south of Manama had been "surrounded... with roadblocks."
Villages have been "caged in with barbed wire," said Maryam al-Khawaja from the Bahrain Centre for Human Rights.
'Draconian new measures'
Wednesday marks the anniversary of Bahrain's independence from the United Kingdom in 1971. It also marks two-and-a-half years since the start of the current unrest in Bahrain, which began with a month-long sit-in at Manama's Pearl Roundabout.
Security forces crushed that protest in March 2011, with the backing of other Gulf countries.
These draconian new measures are disgraceful. National security must not be used as an excuse to sanction the repression of peaceful protests.
Demonstrations have been largely confined to the villages since then, and Wednesday's rally will be the first attempt in months to stage a demonstration in Manama.
As the opposition prepared to mobilise protesters, King Hamad bin Isa Al Khalifa issued a decree last week which bans almost all "demonstrations, marches, assemblies and sit-ins" in the capital.
Earlier this month, he decreed tougher penalties for "terrorism," a term the government sometimes applies to all forms of political dissent.
Parents could be jailed if their children participate in protests, and authorities can revoke Bahraini citizenship from anyone who "commits or incites an act of terrorism."
"The government will forcefully confront the suspicious calls to violate law and order and those who stand behind them," Prime Minister Khalifa bin Salman Al Khalifa said in remarks carried by state media.
There have been scattered acts of violence across the island in recent weeks. A car bomb went off earlier this month in Budaiya, west of the capital, and another one last month exploded near a mosque in Riffa, a largely pro-government town.
But anti-government protesters have largely refrained from violence, and rights groups condemned the new penalties as an effort to ban acts of peaceful protest.
“For years the authorities in Bahrain have shamelessly sought to stifle freedom of expression," said Philip Luther, the Middle East and North Africa director at Amnesty International.
"These draconian new measures are disgraceful. National security must not be used as an excuse to sanction the repression of peaceful protests."
Authorities have also preemptively rounded up hundreds of activists over the past month. One of the most recent was Mohammad Sanad al-Makina, a banker, who was arrested at the airport earlier this month and charged with "inciting hatred against the regime."
Amnesty International called him a prisoner of conscience.
The detainees also include at least five bloggers and photographers, according to Reporters Without Borders.
One of them, Mohammed Hassan, was seized from his home in the early hours of July 31 by dozens of masked policemen. His lawyer was subsequently arrested after saying that Hassan appeared to have been tortured.
Bahrain also last week deported an American teacher for her alleged links to "radical groups," including Hezbollah, the Lebanese political party and militia.
Authorities routinely accuse the opposition of having links to Iran and Hezbollah, but have provided no evidence to back up their claims.
At least 80 people have been killed since the unrest began in Bahrain, according to rights activists, and thousands more injured and arrested.