American and Iraqi troops on Sunday battled in Tikrit, where Iraqi President Saddam Hussein was born.
US military planners had expected remnants of the Iraqi army and Ba'ath party to mount a last stand in Tikrit, 175km north of Baghdad.
In a report from the northern part of Tikrit, al-Jazeera television correspondent Youssef al-Sharif interviewed armed men who said they represented leaders of the 15 main tribal family groups in the city.
They told him they were negotiating a ceasefire.
"We have 15 tribes here and the leaders of the tribes are negotiating with the Americans. We don't want to fight the Americans. The Iraqi military left the city five days ago," one unidentified man told Sharif.
Saddam's concentration of power among his closest family, and distrust of most people outside his Albu Nasir tribe, meant Tikritis formed the backbone of his most loyal military forces.
