Bahrain forces patrol capital on revolt anniversary MANAMA (Reuters) - Armored vehicles patrolled Bahrain's capital on Tuesday in a security clampdown to deter protesters after overnight clashes outside Manama on the first anniversary of a forcibly suppressed pro-democracy uprising. Youths threw petrol bombs at police cars during skirmishes before dawn, prompting authorities to flood Shi'ite villages around Manama with police reinforcements backed by helicopters. Police fired tear gas at two dozen protesters near the former Pearl Roundabout, focal point of last year's protests, nearly hitting several people as canisters bounced off cars. "They fired straight at us, they weren't even shooting in the air," said one protester after a passing driver hauled him into his car. Other groups that appeared later were also doused with tear gas and about 30 people in total were arrested, some of them dragged from their cars on apparent suspicion of being protesters aiming to clog up the highway near the roundabout. Prominent activist Nabeel Rajab, who led the protesters, was detained, as were six American activists in the country as part of a Witness Bahrain group to monitor how police handle demonstrators. The government said in a statement it would deport them. Two others in the group were deported on Sunday after the government said they had entered Bahrain on tourist visas. "People coming to visit Bahrain need to understand that lying on immigration documents is against the law and they will face the consequences of their actions," an immigration department official was quoted as saying. The re-emergence of armored personnel carriers for the first time since martial law was lifted in June underlined the concerns of the Sunni Muslim-led monarchy about a new explosion of civil unrest by Bahrain's disgruntled Shi'ite majority. Shi'ite protests have intensified before the anniversary of the uprising, when mainly Shi'ite protesters occupied Pearl Roundabout for a month before security forces aided by Saudi troops broke up the movement that was inspired by revolts in Egypt, Tunisia and elsewhere in the Arab world. A medic working with an international organization who declined to be named said over 100 people were hurt in clashes in Shi'ite villages around the country, as security forces pinned potential protesters in their districts. He said that of those, 37 were serious injuries. At least 35 people, including security personnel, died during the protests last year. Security forces have not used live fire since that time. An interior ministry statement said rioters caused chaos and vandalism in a number of villages, holding up traffic, but gave no information on numbers of injured or arrested. The growing anger among Shi'ites, who complain that they are treated as second-class citizens, shut out of many state jobs and given limited access to good housing, is a complicated challenge for a Sunni ruling family in power for over 200 years. Bahrain escaped severe international censure for crushing last year's revolt. The Gulf island monarchy is a Western ally, hosting the U.S. Fifth Fleet to counter Shi'ite Iran across the Gulf. Yet the United States suspended a $53 million arms deal until it sees "more progress" by the government on reforms. The closely guarded roundabout, with a now-demolished giant concrete edifice featuring a pearl, was renamed al-Farouq Junction, but is still closed to traffic. Security was beefed up in recent days as opposition activists sought to reclaim the symbolically rich space. On the eve of the anniversary, hundreds of protesters broke away from an authorized opposition party rally to march down the main highway into Manama, heading for the roundabout, before police stopped them with tear gas and rubber bullet pellets. They chanted in favour of Hassan Mushaimaa, a jailed Shi'ite leader who called for a republic last year. The junction remains enclosed by barbed wire on most sides and security guards have set up an encampment nearby. King Hamad bin Isa Al Khalifa, in a televised speech on Monday, told Bahrainis he remained committed to reforms launched a decade ago, a process the opposition dismisses as cosmetic. "This is just one way of expressing our protest," said one, who declined to give his name out of concern for his safety. Analysts say Wefaq, which supports the monarchy, fears losing support to more radical figures such as Mushaimaa. Ali Salman doesn't really know the situation we live in," the young dissident said. February 14 is not only the anniversary of the uprising but also of a 2001 referendum on a national reform charter King Hamad introduced to end a revolt that sputtered through the 1990s. Wefaq and other opposition parties, including the secular Waad led by jailed Sunni politician Ibrahim Sharif, want constitutional changes that would give the elected chamber of parliament the authority to form governments. After last year's unrest, the government granted parliament extra powers of scrutiny over ministers and budgets, but has not budged on the more far-reaching opposition demands. Opposition parties and youths say they have noticed no improvement in police behavior and accuse police of using harsh tactics for political reasons: to suppress dissent in Shi'ite villages that could produce a critical mass of protesters again. Despite the government's professed reform efforts, it has not been enough to convince U.S. lawmakers to unfreeze a planned $53 million arms sale to Bahrain. Bahrain says it needs the hardware, including armored Humvee vehicles and missiles, to defend itself from Iran, which it accuses of fomenting the revolt to turn Bahrain into an Islamic republic. Iran denies this. State Department spokeswoman Victoria Nuland said on Monday that the United States would not go ahead with the deal until Bahrain made more headway in implementing reforms. Addtional reporting by Isabel Coles; Editing by Myra MacDonald