MOSUL, Iraq (AFP) - Five US soldiers were killed on Monday when their patrol was struck by a roadside bomb and attacked with small arms fire in the restive city of Mosul, the US military said.

Iraqi police said fighting had broken out in the east of the city between US troops and unidentified armed men but declined to elaborate. The US military said it was awaiting more details.

US and Iraqi forces are engaged in an extensive operation against Al-Qaeda in the city, where blasts last week killed dozens of people including a police chief.

Iraq's Defence Minister Abdel Qader Jassim Mohammed said the situation in Mosul is "worse than imagined" after touring the flashpoint city on Sunday.

The minister was sharply critical of the Iraqi army's deployment in the city, telling reporters: "The forces are scattered.

"We are working to unify the command The military units are distributed in Mosul in a way that means they haven't studied the area."

"The 2nd Brigade of the Iraqi army works in the day and withdraws at night, leaving the insurgents free to move. There are many negative things and we must address them," the minister added.

"The security generally in Nineveh province is at a good level but in Mosul, the provincial capital, it is bad. The situation ... is worse than imagined by far."

Defence ministry spokesman Major General Mohammed al-Askari said on Sunday that military reinforcements, comprising troops, tanks and vehicles, had reached Mosul for a huge offensive against Al-Qaeda.

He gave no details of the size of the deployment and would not comment on when the operation would begin.

Prime Minister Nuri al-Maliki on Friday promised a "decisive battle" against the jihadists in Nineveh province after last week's devastating blasts.

On Wednesday, according to the US military, a cache of munitions stored by insurgents blew up in a building in west Mosul's Zanjili suburb, leaving a massive crater and damaging about 100 surrounding houses.

A suicide bomber killed provincial police chief Brigadier General Salah al-Juburi and two other officers the next day when they went to inspect the carnage.

Iraqi officials put the toll from Wednesday's blast at 35 people killed and 217 wounded, but the Iraqi Red Crescent in a report on its website said the toll was much higher.

"Many families had buried their killed relatives immediately after the attack without getting them registered," it said.

"This had brought the estimate of the number of killed people to 60; most of them were children, women and elderly," the Red Crescent said.

"At least 280 people were wounded in the attack; some of them are in a very critical situation. It is expected that there are still dead bodies buried under the rubble."

The Red Crescent deplored the blast, which it said "targeted civilians, who repeatedly have been the victims of terrorism in Iraq."

The US military said Mosul was one of its intended targets in Operation Phantom Phoenix, a major countrywide assault on Al-Qaeda launched on January 8.

"Coalition forces recognise the strategic importance of Mosul to Al-Qaeda in Iraq and our operations will continue in the area," said Commander Scott Rye, a US military spokesman.

"This is not a new plan but part of a larger, comprehensive effort to root out Al-Qaeda and disrupt its networks throughout Iraq ... We will continue to coordinate closely with the government of Iraq and Iraqi security forces in our efforts to free all areas of Iraq from Al-Qaeda," Rye told AFP.

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