Mosul - A young Iraqi girl watched her mother die of gunshot wounds in the northern city of Mosul on Thursday, police said.

The girl, who was also wounded, and her mother became the latest in a string of casualties in the city when unidentified gunmen opened fire on a street in western Mosul, roughly 400 kilometres north of Baghdad. It was unclear whether the two were the intended target.

Earlier on Thursday, unidentified gunmen fatally shot two civilians in central Mosul before fleeing, a source in Mosul's police force, speaking on condition of anonymity, told Deutsche Presse- Agentur dpa.

Two civilian bystanders were wounded on Wednesday when a roadside bomb exploded near a US military patrol through the east of the city. The soldiers were not harmed, police said. And in a separate attack Wednesday, unidentified men shot and wounded a government employee.

Earlier this week, Iraqi Prime Minister Nouri al-Maliki said that US forces could stay in particularly violent areas of the country past the June deadline for their withdrawal from Iraqi cities under the terms of a January deal between Iraq and the United States.

Al-Maliki did not say in what areas US forces would stay, but Mosul, with its constant violence, is likely among them.

Mosul, particularly the labyrinthine streets of the predominantly Sunni old city, has long been a stronghold of insurgents.

Iraqi security forces have arrested more than 100 suspected insurgents since they launched "Operation New Hope," an attempt to pacify the city and the surrounding region, but insurgents have responded with near-daily retaliatory attacks. (dpa)