Thousands of Iraqi demonstrators massed again in the city of Ramadi in Sunni-dominated province west of the capital on Wednesday.
It was the third major protest in less than a week in Iraq's largest province of Anbar, once the heart of the deadly Sunni insurgency that erupted after the US -led invasion in 2003.
"This sit-in will remain open-ended until the demonstrators' demands are met, and until the injustice against ends," cleric Hamid al-Issawi told The Associated Press at the protest.
He accused Nour al-Maliki, the Iraqi prime minister's government, of trying to create rifts among Sunnis and Shia's.
"These practices are aimed at drawing the country into a sectarian conflict again by creating crisis and targeting prominent national figures," the cleric said.
The demonstrations follow the arrest last week of 10 bodyguards assigned to Rafia al-Issawi, the finance minister, who comes from Anbar and is one of the central government's most senior Sunni officials.
The case is exacerbating tensions with Iraq's Sunnis, who see the detentions as politically motivated.
Earlier in the week demonstrators gathered along a highway linking Baghdad with neighbouring Jordan and Syria.
They held banners demanding that Sunnis' rights be respected and calling for the release of Sunni prisoners in Iraqi jails.
"We warn the government not to draw the country into sectarian conflict," read one. Another declared: "We are not a minority.''
Iraq's majority Shia rose to power following the 2003 US -led invasion that ousted Saddam Hussein's Sunni-dominated government, though the country's minority Sunni Arabs and Kurds do hold some posts within the government.
Tariq al-Hashemi, the Iraqi vice president, one of the country's highest-ranking Sunni politicians, is now living in exile in Turkey after being handed multiple death sentences for allegedly running death squads, a charge he dismisses as politically motivated.
Al-Maliki has defended the arrests of the finance minister's guards as legal and based on warrants issued by judicial authorities.
He also recently warned against a return to sectarian strife in criticising the responses of prominent Sunni officials to the detentions.
In a recent statement, the prime minister dismissed the rhetoric as political posturing ahead of provincial elections scheduled for April and warned his opponents not to forget the dark days of sectarian fighting "when we used to collect bodies and chopped heads from the streets."
The political tensions are rising at a sensitive time. Iraq's ailing President Jalal Talabani is incapacitated following a serious stroke last week and is being treated in a German hospital.
The 79-year-old president, an ethnic Kurd, is widely seen as a unifying figure with the clout to mediate among the country's ethnic and sectarian groups.