BAGHDAD, Iraq (CNN) -- Coalition troops formally handed over control of Iraq's Babil province to the Iraqi government on Thursday.
Medics treat wounded Ahmed Abdala who was injured in the suicide bombing on Thursday in Baghdad.
Babil, in central Iraq, is the 12th of Iraq's 18 provinces to revert to local security control. It is home to the ancient city of Babylon.
U.S. forces nicknamed northern Babil and surrounding areas the 'Triangle of Death' due to the amount of combat the area experienced earlier in the Iraq war.
Two days before the handover, 15 people were killed in the province in a land dispute between two tribes outside Hilla, according to the Interior Ministry.
Still, the move Thursday came amid a big drop in violence across Iraq and calls from Iraqis for the United States to come up with a troop withdrawal timetable.
A joint statement from the U.S. ambassador to Iraq, Ryan Crocker, and the commander of U.S. forces in the country, Gen. Raymond Odierno, hailed Thursday's handover as "a positive step on the path to Iraq's self-reliance."
"The achievement in Babil Province means that now fully two-thirds of Iraq's provinces have assumed security responsibility," the statement said. "Iraqi Security Forces in Babil have been operating independently for the past several months. Working with local government and military officials, they have demonstrated their readiness to assume responsibility for the provincial security of Babil. Today this responsibility is theirs."
The statement said U.S. forces will "assist as needed."
Last month, coalition troops handed over Anbar province to Iraqis.
The other provinces that have transitioned to Iraqi security control are Duhuk, Irbil and Sulaimaniya in the Kurdish region, and Karbala, Najaf, Qadisiya, Muthanna, Thiqar, Basra, and Maysan in the Shiite south. Baghdad, Diyala, Salaheddin, Nineveh, Kirkuk and Wasit remain under U.S. control. View a map of the provinces »
While bloodshed has decreased overall, violence hit central Baghdad on Thursday as a suicide bomber rammed his explosives-laden vehicle into the Iraqi labor minister's convoy, killing 11 people, officials said.
Minister Mahmoud Mohammed al-Radhi was not in the convoy when it was attacked in a busy commercial area of the city at about 8 a.m., an Interior Ministry official said.
The attack wounded 22 people, including some of the minister's security guards and some civilians.
Al-Radhi, a Shiite, was approved as labor and social affairs minister by the Iraqi parliament in May 2006.
CNN's Yousif Bassil contributed to this report