Gunmen have stormed a house and killed five people in the northern Iraqi city of Samarra, police said on Sunday.

"The only nine-year-old survivor said that four masked armed men wearing Iraqi army uniform stormed the house late Saturday, and killed five of his family," a police officer in Samarra hospital told Xinhua on condition of anonymity.

The boy was hiding in the house when the masked men gunned down his parents, sister and two brothers in cold blood, the officer said.

According to initial inquiry with neighbors, the father was accused by militants of collaborating with US forces, the officer said.

Samarra, some 110 km north of Baghdad, has been a hotbed of insurgency against US troops and Iraqi security forces.

Source: Xinhua