Tens of thousands of Sunni Muslims have rallied in several Iraqi cities to protest what they describe as unfair treatment by the country's Shia-led government.
Sunnis have held a number of protests since last December demanding that Prime Minister Nouri al-Maliki, a Shia, step down, and are calling for the release of thousands of Sunnis they say were rounded up arbitrarily under the guise of counter-terrorism regulations.
They also want authorities to rescind policies they say discriminate against Sunnis.
Protesters had hoped to move their demonstrations from predominantly Sunni provinces to Baghdad on Friday, but they backed off that plan after the government rejected their request and imposed tough security measures.
Government security forces blocked roads leading from Sunni-dominated provinces and sealed off all Sunni neighbourhoods.
In the western cities of Fallujah and Ramadi, demonstrators blocked the main highway to Jordan and Syria to perform Friday noon prayers. Others gathered in main squares in the northern cities of Samarra, Mosul and Kirkuk. Local residents rallied outside a prominent Sunni mosque in Baghdad.
"Where is the partnership you are talking about? Sunnis are only seeing genocide and marginalisation," shouted cleric Saad al-Fayadh in front of thousands of worshippers in Ramadi.
His speech was interrupted many times by demonstrators who pumped their fists in the air and shouted: "God is great."
To ease tension, the government formed a committee to consider the Sunnis' demands. It has released about 3,000 detainees and is working on clearing thousands of Saddam Hussein-era officials to allow them to take their pensions or sell properties that were blocked after 2003 US-led invasion.
Last month, at least five stone-throwing protesters were killed when soldiers opened fire in Fallujah. The government has promised to investigate the incident, which marked the first time protesters had been killed in the unrest.