A Shia tribal leader and 10 members of his family were killed in a shooting north of the Iraqi capital, Baghdad, police have said.
Sheikh Hussein Sarhan al-Hayali, who employed his son and nine others on his farm in Balad, were rounded up by unidentified gunmen and shot dead.
Balad, a mainly Shia town, has been the scene of many insurgent attacks.
In another incident, an Iraqi army major and his son were shot dead by insurgents in Taji, north of Baghdad.
And in the northern city of Tikrit, an Iraqi contractor, who supplied food and water to the Iraqi army, was killed by gunmen.
Sheikh Hayali's 15-year-old son, who suffered bullet wounds to his arms in the attack in Balad, said the men had been ambushed when they arrived at the farm to start work in the morning.
"When we arrived at the farm at about 0800 (0500 GMT), we were ambushed by nine gunmen who had covered their faces," Gazwan Hussein told the Reuters news agency.
"They told us to sit down. When my father tried to pull the pistol from the pick-up truck, they opened fire immediately," he added.
The gunmen then fled in the vehicle.