Residents gather at the site of a bomb attack in Baghdad's Hussainiya district, on May 6, 2013. The recent increase in sectarian violence in Iraq is testing the government of Nouri al-Maliki. (SAAD SHALASH/REUTERS)

A recent tide of sectarian tensions that erupted into the worst violence seen in Iraq in five years is testing the government of Prime Minister Nouri al-Maliki, whose ability to contain the crisis could hinge on a conflict raging beyond his control in Syria.

The prospect of a regional power shift driven by the bloody civil war next door, where a mostly Sunni rebel movement is struggling to topple the Shiite-dominated regime, has emboldened Iraq’s Sunni minority to challenge its own Shiite government and amplified fears within Maliki’s administration that Iraq may soon be swept up in a spillover war.

Sectarian bombings and assassinations targeting both Sunnis and Shiites increased last month after government forces raided a Sunni protest camp in northern Iraq, killing more than 40 people. Bombings continued Wednesday and Thursday, leaving more than 30 people dead in Shiite neighborhoods of Baghdad.

Meanwhile, Iraq’s embittered Sunnis say the successes of the Syrian rebels have given them the confidence to challenge what they call worsening government discrimination and abuse against the minority that once ruled this country under Saddam Hussein.

Iraq’s Sunnis have been staging a growing wave of anti-government demonstrations in Sunni-majority provinces across the country for five months, raising tensions that some say could reignite the civil war that peaked in 2006. The combustible situation, underpinned by what critics call mistakes of the decade-long U.S. occupation that enshrined sectarianism, has been aggravated by Maliki’s increasingly authoritarian policies, analysts say.

The government has labeled the protest movement a project of Hussein’s former Baath Party and of al-Qaeda, an allegation denied by Sunni participants, who say they represent a cross section of Iraqi society.

They list among their key grievances laws and practices codified under U.S. occupation that bar former Baathists from participating in public life and authorize the use of secret informants — many of them originally cultivated by the U.S. military — whom human rights groups say Maliki uses to target Sunnis.

But the April 23 assault on the Sunni camp in Hawijah, coupled with increasingly antagonistic rhetoric from clerics and political leaders on both sides, has injected an ominous militant tone into what had been a largely peaceful protest movement. Last month, tribal leaders in the Sunni heartland of Anbar province announced the formation of a “tribal army” to protect demonstrators; residents say the force has drawn heavily from jihadist groups such as al-Qaeda in Iraq and the Islamic State of Iraq.

Meanwhile, at least two powerful Shiite militia leaders have rallied followers to crush the protest movement, which they, like the government, say is dominated by terrorists. On Thursday, government forces raided the home of a leading protest leader in Ramadi.

Some government officials and Sunni tribal leaders have made conciliatory gestures to pull Iraq back from the brink of a sectarian war, the kind that destroyed families and divided neighborhoods less than a decade ago. A parliamentary committee launched an investigation of the Hawijah raid, and several prominent Shiite officials called it a mistake. Last week, a group of Sunni sheiks in Anbar sent aid to flood victims in Shiite-majority areas of Iraq’s south.

Early last month, in a bid to appease protesters, Maliki’s cabinet proposed legal reforms that included amendments to weaken the laws that Sunnis say are used to discriminate against them. But the legislation has stalled in parliament amid fierce Shiite opposition.

Syria’s pivotal role

The muted state of unease, after the strife last month, may be a “false peace,” said Erin Evers, a Middle East researcher for Human Rights Watch.

Sunni protest leaders and some officials close to Maliki said that they remain pessimistic about the prospect of a long-term solution and that the war in Syria could become the deciding factor.

Inside a dust-battered tent at a protest camp in Fallujah last week, tribal leaders in white robes described the conflicts in Syria and Iraq as inescapably intertwined. Many here view Maliki as a puppet in a conspiracy by Shiite-majority Iran to achieve regional domination, and they say Syria’s Iran-backed regime is no different.

“Maliki’s intentions for the Sunnis are the same as Iran’s: They want to ‘Shii-ify’ the country,” said Mohamed al-Bajari, a spokesman for the protest movement in Fallujah. Bajari served as an officer in Hussein’s intelligence service.

At a rally last Friday on a highway that cuts through Fallujah, where the old flag of the Hussein-led Iraq fluttered above the crowd, one banner read: “America: You gave Iraq to Iran, and then you left.” Another, directed at Maliki, read: “If you don’t understand it in Arabic, we’ll say it in Persian: Leave.”

A rebel victory in Syria could benefit Sunnis in Iraq, Bajari said.

“When Iran loses Syria, that means they’ll lose influence here,” he said. “The new regime in Syria will be Sunni. So in these provinces, our backs will be protected by a Sunni regime.”

But as with the Syrian opposition, the credibility of Iraq’s largely peaceful Sunni protest movement is being undermined by the growing participation of jihadist groups, which tribal leaders have sought to play down but do not deny.

The attack in Hawijah signaled a warning to the sheiks of Anbar that their towns could be next, said one local journalist, who spoke on the condition of anonymity for fear of reprisal from the government or Sunni militants. That led protest leaders to “accept” jihadists as part of their tribal army, the journalist said.

Last Friday, Fallujah residents present at the rally said militants fanned out in the area to watch for encroaching government troops.

“All insurgent groups, including al-Qaeda, have united around one thing, which is to protect the demonstrations,” the journalist said.

Government officials say the emergence of the tribal army is evidence that al-Qaeda — which last month exchanged pledges of allegiance with the Islamist Syrian rebel group Jabhat al-Nusra — has infiltrated or is leading the protests.

The Islamic State of Iraq, a group affiliated with al-Qaeda, asserted responsibility for the killings in March of dozens of Syrian government troops who had temporarily retreated across the border into Anbar.

Hurdles for Sunnis

Despite their increasingly angry rhetoric, Sunnis are divided, analysts say.

A number of Sunni officials in Baghdad have lost credibility with the protest movement for their willingness to work with Maliki. In Anbar, tribal leaders, militants and protesters have sparred over the path forward.

Even as Khaled Hamoud al-Jumeili, the tribal leader organizing the weekly protests in Fallujah, called for a continuation of peaceful demonstrations last week, the Iraqi Islamic Party distributed surveys at local mosques to poll residents on what form of action — war or secession — they preferred, residents who participated in the protest said.

Meanwhile, tribal leaders say the government has created a new “Awakening” movement, modeled after the Sunni tribal alliance that the U.S. military recruited and paid to help pacify Anbar and defeat insurgents in 2007.

Maliki “formed the new Awakening to foment strife and to make it look like the sheiks here are with the government,” Bajari said. Ali al-Moussawi, a Maliki spokesman, said that no new movement had been formed but that the existing Awakening has been expanded and is under new leadership.

Ramzy Mardini, an adjunct fellow at the Beirut-based Iraq Institute for Strategic Studies, said that the Sunni minority is facing a much stronger adversary in today’s Iraqi government than it did at the height of the country’s civil war and that the odds are against them.

Sami al-Askari, a member of parliament from Maliki’s Dawa party, said the protests derive from an unwillingness by some Sunnis to accept the political reality of a post-Hussein Iraq, where demography ensures that the prime minister’s post, the parliament and the security forces are likely to be dominated by Shiites for a long time.

“The Sunnis in Iraq were the rulers for centuries. And, suddenly, the situation has changed,” Askari said. “The Sunnis know very well they cannot win this war.”

A Washington Post employee in Fallujah contributed to this report.