A car bomb detonated in a busy Baghdad market on Friday, police and hospital officials said, killing at least 14 people and ending what had been a relatively quiet holiday period in the Iraqi capital.

At least one woman and a child were among the dead, a police officer said on condition of anonymity as he was not authorized to talk to the press. Both the officer and a hospital official who also would not give his name, said 14 people were killed and 64 wounded.

The popular market in Tayaran Square — a predominantly Shiite area that has been targeted by insurgents in the past — was full of shoppers heading home from Friday prayers. In late May, a car bomb killed 23 people in the square.

Violence across the country is down nearly 60 percent, according to the U.S. military, largely because of an influx of American troops in the capital and the growth of anti-Al Qaeda in Iraq groups in Anbar province and elsewhere.

But unrest still plagues Diyala province just north of Baghdad, where U.S. commanders say many of the militants that held parts of the capital earlier this year have fled.

The U.S. military said it had killed four gunmen tied to Al Qaeda in Iraq in an operation Friday near Muqdadiyah in Diyala. Another was killed in a predominantly Sunni area south of Baghdad.

American and Iraqi troops have increased operations in Diyala in recent weeks.

On Thursday, the U.S. military said that it had killed 12 suspected terrorists and detained 37 others during a Dec. 22 to 25 operation near Muqdadiyah.

Meanwhile, U.S. and Iraqi forces found guns, bombs and explosives underneath a chicken coup property belonging to the son of a top Sunni lawmaker.

In Seoul, South Korea's parliament voted Friday to extend the country's troop deployment in Iraq for another year, amid protests by activists opposed to the decision. South Korea has 650 troops in Iraq.

Meanwhile, an official with Iraq's oil ministry said late Thursday it had threatened to stop all crude exports to South Korea if that nation proceeds with a deal it signed with the semiautonomous Kurdistan regional government.

The central government has promised to not do business with oil firms trying to get a foothold in Kurdistan before a new oil revenue-sharing law is passed.

In early November, a consortium led by the state-run Korea National Oil Corp., or KNOC, secured exploration rights from the Kurdish regional government for an oil field in the northern province. The Korean consortium includes SK Energy, South Korea's biggest oil refiner, and GS Holdings Corp.

"The ministry has made it clear that no contracts should be signed until a new national oil law is passed," Assem Jihad, a ministry spokesman, told The Associated Press. "There was a clear warning to these companies that they will be blacklisted and excluded from any future cooperation with the ministry."

According to KNOC, through November South Korea had imported 42 million barrels of oil from Iraq, nearly triple all its imports from the country last year. Iraq is the sixth-largest provider of oil to the country.

The Kurds have signed more than a dozen contracts with foreign oil companies, insisting Iraq's constitution gives them that authority. The Iraqi Oil Ministry insists the contracts are illegal.

Iraqi authorities have drafted numerous versions of legislation to regulate the country's oil industry and share the revenues among Shiite, Sunni and Kurdish communities.

But the effort has bogged down parliament in large part because of opposition from the Kurds, who want a greater say in managing oil fields in their self-ruled area of the north.

U.S. officials view the oil law as a catalyst for investment and a means of tamping down sectarian violence. Most of Iraq's oil reserves are in the Kurdish north and the largely Shiite south. The provinces where most Sunnis live have few proven reserves, leading to suspicions they will be left out of oil profits.

Iraq is now exporting 1.9 billion barrels of oil a day, compared to 1.5 million a day earlier this year, according to U.S. statistics.