Thousands marched in a northern Iraqi city Tuesday, demanding political reforms and an investigation of the fatal shootings of two protesters last week.

The peaceful rally by 5,000 in the city of Sulaimaniyah was a sign of growing frustration with the tight control of two ruling parties over the economy and politics in the self-ruled Kurdish region.

"Killing of the civilians was a red line," said Nasik Kadir, 40, one of the protesters in Sulaimaniyah, 160 miles (260 kilometers) north of Baghdad. "What happened that day, it became a kind of turning point."

Kurds in the self-ruled region in Iraq's north generally have a higher standard of living and more security than the rest of the country, but many seek more political and econonomic freedom.

Last Thursday, hundreds of protesters inspired by successul anti-government uprisings in Tunisia and Egypt converged on the Sulaimaniyah headquarters of the Kurdistan Democratic Party, which is headed by the president of the self-ruled Kurdish region. Some protesters pelted the building with stones, and security guards opened fire. Two people were killed and dozens injured.

Protesters have rallied daily since the incident. Two more people were killed in clashes between security forces and demonstrators.

The heads of the main political groups in the Kurdish region held a meeting late Monday to try to reduce tensions and address some of the grievances of the protesters, but no agreement was reached.

Many well-known Kurdish artists, singers and actors calling themselves the "White Fence" came out to Tuesday's protests wearing white sheets. They deployed among the protesters and security forces to deter violence.

Iraqis across the country are gearing up for protests Friday, in what organizers have billed a "Day of Rage." Protesters seek better services and an end to corruption.

Iraqi officials have scrambled to show they are addressing such concerns by cutting politicians' salaries, allocating more food to the needy and cutting back on electricity tariffs.