Various reports on Friday suggested that Iraqi police and national guardsmen had disappeared from view and masked armed men were wandering freely around Iraq's second largest city.
A main road to the local governorate and police station was littered with roadside bombs, making movement in the heart of the city hazardous.
Lieutenant-Colonel Paul Hastings, the US military spokesman in Mosul, however, said the "governor is actively involved in restoring police presence and is in control of the security situation in the city".
"Mosul is not out of control nor is the city in the control of the insurgents," he added.
Control the streets
Witnesses in Mosul told Aljazeera.net that major sections of the city had been seized by anti-US fighters who were patrolling the streets.
US forces have come under
fierce mortar and RPG attacks
"They control the streets, no one is going out for fear of more US air strikes," Abd Allah Ghafar, a freelance journalist in the city, told Aljazeera.net by telephone.
"The situation is very bad, there is no security, only armed resistance groups on the streets and it seems there is no government in Mosul," he said.
Another Mosul-based journalist told Aljazeera that US armoured vehicles were forced to retreat from two main bridges they had blocked off after coming under a fierce mortar barrage and rocket-propelled grenade (RPG) fire.
"US forces have separated the two sides of Mosul city by deploying armoured vehicles on the bridges linking them," Muhammad Dhu al-Nun said.
"However, these armoured vehicles have come under fierce attacks by mortar shells and rocket-propelled grenades, forcing them to withdraw and return to their bases."
Armed local fighters now control
Mosul's streets, say journalists
"The city is now calm," he added.
But US military spokesman Captain Angela Bowman explained that retreat was carried out at the request of the governorate to allow civilians to attend weekly prayers at the mosques.
Bowman admitted there were "pockets of resistance".
"In the southwestern area there are terrorists and insurgents on the streets but this is not city wide. We are still well in control," she said.
A night-time curfew, imposed earlier in the week initially until Friday, will remain in place from 4pm (1300 GMT) until 6am, Hasting said, without specifying when the order would expire.