At least 32 people have been killed and 100 wounded by a car bomb in a market area in Kirkuk, Iraq.
Police said the blast went off as people did their evening shopping in the outdoor Shurja market at around 6pm on Tuesday.
Kirkuk is about 250km from Baghdad.
The explosion came as American troops completed their withdrawal from towns and cities in Iraq, six years after the invasion. The pullback was declared a national holiday.
American and Iraqi commanders have warned they expect al-Qaeda and other groups to attempt to re-ignite sectarian tensions.
More than 70 people were killed in a truck bombing in Kirkuk 10 days ago.
The BBC reports that some 131,000 US troops remain in Iraq, including 12 combat brigades, and the total is not expected to drop below 128,000 until after a national election in January.
All troops will be gone from Iraq by the end of 2011.