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.

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.