A car bomb exploded Thursday in a crowded livestock market selling sheep, cattle and goats south of Baghdad, killing at least 12 people and wounding dozens, Iraqi police and medical officials said.

The parked car exploded at the height of the morning buying and selling at the market on the outskirts of Hillah, 60 miles south of Baghdad, said Iraqi police Maj. Muthana Khalid. The blast scattered bodies and animal carcasses throughout the market, a witness said.

While violence has declined dramatically in Iraq during the past 18 months, there are concerns about a possible upward trend in bloodshed after a series of high-profile attacks on civilians and U.S. and Iraqi security forces in recent weeks.

All the dead and injured in Thursday's bombing were civilians, Khalid said.

Dr. Ahmed al-Hasnawi, from the Hillah General Hospital, said 60 people were wounded but two of them died after being taken to the hospital.

The U.S. military put the casualty toll at 10 dead and 56 wounded.

Markets, mosques and religious shrines have been a favorite target of insurgents in Iraq because of the possibility of high casualty counts.

Dozens of cattle merchants, farmers, butchers and buyers were at the market in Hamza al-Gharbi, a mostly Shiite community a short distance from Hillah, when the bomb exploded.

The market operates daily but is at its busiest on Thursdays and Fridays, said cattle merchant Rajab Abdul-Hussein.

Mohammed Abbas, a butcher, described a grisly scene of bodies and animal carcasses strewn throughout the market in the aftermath of the bombing.

"Blood and meat were everywhere," Abbas said.

Witnesses told police the blast came from a car parked near the market's main thoroughfare.

The Hillah area has been the site of many deadly bombings, including one of the worst attacks in Iraq since the 2003 U.S.-led invasion. In February 2005, a suicide car bomber killed 125 national guard and police recruits in Hillah.

In March 2007, two suicide bombers struck a crowd of Shiite pilgrims, killing 120. And in February that year, suicide bombers struck a market, killing 73.

In Baghdad Thursday, gunmen ambushed an Interior Ministry official on his way to work, seriously wounding him, said an Iraqi police official, who spoke on condition of anonymity because he was not authorized to release information.

Meanwhile, one of Iran's most powerful political and religious figures, former Iranian President Hashemi Rafsanjani, met with influential Shiite cleric Grand Ayatollah Ali al-Sistani Thursday in the holy city of Najaf.

Rafsanjani has met with various government and religious officials since his arrival in Iraq on Monday.

Some Sunnis have protested Rafsanjani's trip, including hundreds who took to the streets in the western city of Ramadi on Wednesday. Iraq's Sunni Arab minority has lost the dominant position it enjoyed under its patron Saddam Hussein and is wary of the growing influence of Shiite Iran.

Iraq's Sunni vice president, Tariq al-Hashimi, canceled a planned meeting earlier in the week with Rafsanjani, citing previously scheduled engagements, according to al-Hashimi's Web site.