(CNN) -- Nearly 6,000 protesters flooded the center of the Iraqi city of Mosul on Friday, defying a curfew imposed one day earlier by military authorities seeking to control tensions tied to the looming withdrawal of U.S. troops from the country.
The demonstrators demanded a rejection of any extension of the American military presence beyond the end of 2011. Although the U.S. combat mission in Iraq officially ended last year, roughly 50,000 American troops are expected to remain in the country until the end of the year to train, assist and advise Iraqi troops.
Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, said Friday that Iraqi officials have not asked the Obama administration to push back the withdrawal deadline. Any discussion about a change in the timetable would be considered, he indicated, but would need to begin soon.
"Since April 9, thousands of angry demonstrators have been rallying in Nineveh province (which includes Mosul) and holding sit-ins," Mosul Gov. Atheel al-Nujaifi told CNN. "The protests have been very peaceful, but two days ago the military operation command (was) ordered to end" them.
The protesters were also demanding the release of a number of men allegedly detained for years without facing any charges, local journalists and witnesses told CNN.
Al-Nujaifi said clashes between the protesters and Iraqi troops resulted in the death of one protester. Another was critically wounded, he said.
Mosul, a largely Sunni city, has been a hotbed of ethnic and sectarian strife.
CNN's Mohammed Tawfeeq contributed to this report