Falluja, Iraq  - At least nine people were killed and 31 others were injured when a bomb attached to a minibus exploded in the western Iraqi city of Falluja on Tuesday, police said.

The blast in the Amiriyat al-Falluja district left shops and restaurants as twisted, smoking rubble. Police told the German Press Agency dpa that they believed al-Qaeda was behind the attack.

Falluja, which lies in Iraq's Sunni Muslim heartland some 60 kilometres west of Baghdad, was once the site of some of the heaviest fighting between Sunni insurgents and US and Iraqi soldiers.

The city and its environs have been quieter since US and Iraqi authorities enticed many militants to join government-allied militias with promises of money, weapons, training and jobs in the Interior Ministry, though sporadic attacks, particularly targeting those who work with the government, continue.

Some 400 kilometres to the north, in Mosul, a local official charged that the military had arrested more than 200 people in a "unprecedented" security sweep without informing the provincial government.

"More than 200 people, including officers, university professors, seniors and merchants were arrested from their homes in these unprecedented arrests," Abdel-Rahim al-Shammari, head of the Security and Defence Committee in the provincial government, told dpa.

Al-Shammari charged that "the military conducted the operation under direction from Baghdad, with soldiers from Baghdad, and that the provincial council was not informed."

He stressed that the provincial council "rejected" the move, and demanded the central government provide an explanation.

Mosul and its environs are among the most ethnically and religiously diverse areas of Iraq, but remain the site of near-daily, deadly attacks.

The Arab-nationalist provincial government elected in January has sometimes been at odds with the central government in Baghdad over security arrangements, particularly in the areas of the province bordering northern Iraq's semi-autonomous Kurdish region.  dpa