Iraqi forces have been handed control of security in the province of Babil, south of Baghdad, by the US military.

It is the twelfth of Iraq's 18 provinces to be handed back to Iraqis.

The handover on Thursday came just two days after clashes in the mainly Shia province killed at least 15 people and scores more wounded.

Babil had been the forefront of sectarian violence, including a suicide attack in Hilla, the provincial capital, in March 2007 that left more than 100 Shia pilgrims dead.

The previous province transferred to Iraqi security control was Anbar - once the centre of Iraq's Sunni revolt - which was handed back in September.

'Security gains'

Mowaffaq al-Rubaie, Iraq's national security adviser, said at the handover ceremony in Hilla that domestic security forces would soon take over the nearby province of Wasit from the US military.

"I want to declare from Babil that Iraq will take over Wasit in the next few days and we hope to complete the transfer of the remaining provinces in the near future," al-Rubaie said.

"Today the security forces of Babil are self-reliant and we are proud to take over Babil from US forces."

The handover ceremony was attended by senior US officials, including Lieutenant-General Lloyd Austin, the number two commander of US forces in Iraq.

With the transfer of the province, American forces will retreat to their bases and become involved in security operations only at the request of the provincial governor.

Baghdad, Diyala, Salaheddin, Ninawa, Kirkuk and Wasit remain under US control.