Iraqi officials say gunmen have killed seven Sunni construction workers in an attack northeast of Baghdad.

Police officials say the attackers opened fire on the workers from a speeding car as they were building a house in the village of Abara, about 65 kilometers (41) miles from the Iraqi capital.

The officials say the workers were all related and were from a Sunni tribe.

Violence has spiked in Iraq since a deadly security crackdown on a Sunni protest camp in April. The surge in attacks has raised fears about a return of the sectarian bloodshed that pushed the country to the brink of civil war in 2006-2007.

At least 157 people have died in attacks in Iraq so far this month, according to an Associated Press count.