MANAMA  - 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 flung 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 as 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 detained and taken away. 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.

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 US 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. Street battles ensued with youths throwing petrol bombs, rocks and iron bars. They chanted in favor 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) marked the launch of a development and modernization process, which is still moving forward to meet the aspirations of our loyal people in all areas,” said the king.

He said he had pardoned 291 prisoners, but they did not include those arrested during last year’s revolt. The opposition demand the release of 14 leading figures who were jailed by a military court for allegedly trying to stage a coup.

Young men justified this week’s disturbances by saying they were in constant conflict with police who treat them harshly. “This is just one way of expressing our protest,” said one, who declined to give his name out of concern for his own safety.

He said they were ignoring calls by Sheikh Ali Salman, head of the leading Shi’ite opposition party Wefaq, not to throw petrol bombs. Analysts say Wefaq, which supports the monarchy, fears losing support to more radical figures such as Mushaimaa.

“We respect the opposition but everyone has to choose their own path. 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.

Opposition parties say the constitution promulgated a year later was a disappointment because it neutralized the powers of an elected assembly with an upper house of royal appointees.

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.

Bahraini authorities have hired US and British police chiefs to help reform policing after revelations about torture and deaths of detainees during last year’s crackdown.

One of them, former Miami police chief John Timoney, told Reuters this week the interior ministry was serious about reform and would hire Shi’ites in a new recruitment and training drive, but he said youth violence was posing obstacles.

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 US 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 non-Arab Shi’ite giant 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.

She called for more progress, including reinstatement of Bahraini workers unfairly dismissed from their jobs and resolution of court cases related to political expression.

“More remains to be done on that. Assistance is still on pause ... We’re not going to go forward until we see more progress,” Nuland told reporters.

The State Department last month authorized the dispatch of $1 million of equipment to Bahrain to support US operations in the region, including the Fifth Fleet.