Gunmen kidnapped 20 men on Friday who were travelling from northern Iraq to Baghdad for medical tests needed to join the army, but the hostages were later freed in an army operation, officers said.

They were seized at Al-Amin restaurant near Baiji, a police lieutenant colonel said, adding that the kidnappers took them in eight vehicles toward Anbar province, which is home home to various former insurgent strongholds.

A colonel from the army's 4th Division, which is responsible for the area where the incident occurred, confirmed that 20 people were kidnapped near Baiji, but did not provide details.

The army officer later said four Al-Qaeda members were arrested and the 20 people who were kidnapped were freed, and that they were now at an army base in central Tikrit.

The police officer said the 20 were freed in an army operation about 80 kilometres (50 miles) west of Baiji in which four of the kidnappers were arrested.

Kidnappings were common during the worst years of sectarian violence in Iraq, but have declined since then.

Violence has also dropped significantly from its peak in 2006 and 2007, but attacks, which usually target security forces, government officials or members of Iraq's Shiite majority, remain common.

PM warns of 'ethnic conflict' in Iraq
Baghdad (AFP) Dec 1, 2012 - Prime Minister Nuri al-Maliki on Saturday warned of the danger of "ethnic conflict" in Iraq, after negotiations aimed at easing Arab-Kurd tensions in the country's north stalled this week.

"If conflict erupts, it would be unfortunate and painful, and it will be an ethnic conflict" that is "not in the interest of Kurds nor Arabs nor Turkmen," Maliki told a news conference in Baghdad.

Talks between federal and Kurdish security officials aimed at easing high tensions between the two sides in northern Iraq broke down over Baghdad's refusal to scrap the Tigris Operations Command, the autonomous Kurdistan region's government said in a statement on Friday.

The establishment of the federal Tigris Operations Command, which covers disputed territory in northern Iraq, has drawn an angry response from Kurdish leaders who want to incorporate much of the area into their region.

Maliki also defended federal troop movements in the north, saying it is the army's right "to be in any part of Iraq."

And he ruled out the redeployment of US forces to help ease the tensions, saying it is "the responsibility of the Iraqi government and the (Kurdistan) region to work to end their problems without the assistance of a third party."

US forces played a coordinating role between Kurdish and Arab forces in disputed territory, forming joint patrols and checkpoints comprised of US soldiers, Iraqi troops, and Kurdish forces.

But US troops withdrew from Iraq last year, removing a buffer to Arab-Kurd tensions.

The dispute over territory in northern Iraq is the biggest threat to the country's long-term stability, diplomats and officials say. Ties between Baghdad and Kurdistan are also marred by disputes over oil and power-sharing.