Police Captain Mohammed Ibrahim said gunmen broke into the house of Dawood Nuri Mohammed al-Ari and killed him, along with his wife and two daughters.

"The eight-year-old daughter, Sunoor, was slaughtered," he told AFP indicating that her neck was cut from her body.

Ibrahim said the killings appeared to be sectarian as "nothing was stolen" from the family's home.

In the past few months, insurgents have stepped up attacks in and around Kirkuk, an ethnically volatile city claimed by both Arabs and Kurds.

Longstanding Kurdish demands for the city to incorporated in their autonomous region in northern Iraq are to be put to a referendum before December 30.