RAMADI, Iraq - Sunni protesters are camped out in dozens of tents festooned with tribal banners on the edge of this one-time Iraqi insurgent stronghold.
They are digging in and growing more organized, vowing to keep up their demonstrations against a Shiite-led government they feel has left them behind.
The protesters will seek to bring down the government if their demands aren't met, warned a prominent Sunni sheik who once helped Americans battle al-Qaida in Iraq.
He spoke ominously that armed militants who once fought U.S. troops could rally to the cause.
"When we give up hope that the government can reform itself, we will call for toppling it," Sheik Ahmed Abu Risha said in his well-guarded family compound near the banks of the Euphrates. "If this government does not disband itself, we will head to Baghdad and stage protests in the streets and paralyze the government's work until it falls apart."
When the last U.S. troops withdrew from Iraq in December 2011, there was hope that majority Shiites and minority Sunnis and Kurds would learn to work together, resolve their differences and create a healthy democracy in a country with a history of strong-arm rule.
But as the 10th anniversary of the March 20, 2003, U.S.-led invasion approaches next month, the same sectarian tensions stirred up by the war are flaring again - in no small part, many Sunnis say, because of Prime Minister Nouri al-Maliki's attempts to consolidate power.
Nobody is predicting a return to open warfare. The Sunnis know they stand little chance of overpowering the Shiites, who dominate the government, army and police. Nor do the majority of Iraq's Sunni Arabs, including protesters, support al-Qaida and its frequent widespread bombings of Shiite targets.
But Abu Risha's comments in an interview on Monday with The Associated Press point to growing impatience among demonstrators in the western province of Anbar and other predominantly Sunni areas. Their bitterness has increased since the shooting deaths of several demonstrators by Iraqi security forces in Fallujah last month.
Abu Risha carries considerable weight in Anbar. He took over leadership of the province's Sahwa movement, a Sunni tribal militia that joined the U.S.-led fight against insurgents, after his brother was assassinated in 2007. The Sahwa members' decision to fight alongside American forces is widely credited with helping turn the tide against al-Qaida.