"The hospital received 12 bodies, including two women, and 26 injured, most of them civilians," said a doctor at Mosul's Medical City hospital, after violent clashes broke out between
the fighters and police on Wednesday.
Two of the fatalities occurred when a roadside device exploded on Baghdad Street just as a US military convoy passed by.
Aljazeera's correspondent reported that explosions were being heard in al-Najjar and al-Ghazlani neighbourhoods of Iraq's third largest city.
He said the death toll was later revised to 14 fatalities and 52 wounded.
The Reuters correspondent in Mosul quoted witnesses as saying Iraqi police and armed fighters were fighting with rifles and rocket-propelled grenades (RPGs) on the streets.
Area sealed off
The Reuters correspondent said one firefight began at about 12.45pm (0845 GMT) in the Sinjar neighbourhood to the southwest of Mosul.
Many of the civilian fatalities are
from blasts aimed at US soldiers
Other battles were raging to the north, in the centre and to the south of the city, he said.
"I can hear gunfire and RPGs in the Yarmuk area to the northwest, in the city centre and in al-Razlani to the south," he said.
It was not immediately clear if there were any dead or wounded from the clashes.
He said the police had tried to seal off the Sinjar area and were battling the fighters street-to-street near the highway.
US troops were not believed to be involved in the clashes.
The crack of small arms and assault rifles could be heard in
"The bomb went off at 10.35am in the Mamun neighbourhood, killing
a man and a woman and wounding
Capt Hamad Hasan Abd Allah,
the background, and at least two loud blasts sounded, possibly the noise of RPGs striking their target.
Mosul has seen frequent outbreaks of violence over the past year, most recently a car-bomb attack outside a police station in the city centre last week which killed five people.
There have also been regular attacks on occupation troops
stationed in and near the city, and occasional drive-by shootings in which Iraqi officials and US soldiers at checkpoints have been targeted.
Referring to the roadside blast in which two Iraqis died in central Mosul, Iraqi police Captain Hamad Hasan Abd Allah said: "The bomb went off at 10.35am (0635 GMT) in the Mamun neighbourhood, killing a man and a woman and wounding two people."
The US military said none of its personnel were hurt in the blast.
A doctor at Mosul's general hospital said pieces of shrapnel had been removed from the two injured people, who were in a stable condition.