BAGHDAD – An Iraqi interpreter for the U.S. military was gunned down on Friday by his son and nephew north of the capital after he refused their demands to quit his job, a police official said.

The attack occurred as at least 16 people were killed nationwide, a grim reminder of the dangers facing Iraqis despite a sharp drop in violence over the past few years.

Hameed al-Daraji was shot in the chest in his house in Samarra, 60 miles north of Baghdad, police Lt. Emad Muhsin said.

Muhsin said al-Daraji worked as a contractor and translator for the U.S. military since 2003 against the wishes of his family. His relatives were constantly fighting with al-Daraji to give up working with the Americans, but he ignored their pleas, he added.

Al-Daraji’s son and nephew were arrested after the attack and confessed to being members of an al-Qaida group that sanctioned the killing, Muhsin said, adding that police were searching for a second son suspected of being an accomplice.

Iraqis working for the U.S. military in the country have been targets of extremist groups who view them as traitors and collaborators with an invading country. But it is rare for family members to kill a relative because of his or her employment with the Americans in Iraq.

Car bombs, meanwhile, tore through two neighborhoods in restive cities north of Baghdad in separate attacks targeting a police captain and a provincial council member.

The deadliest attack was in the northern city of Tuz Khormato when an explosives-laden car blew up about 50 yards from the house of Niazi Mohammed, a Turkomen member of the Salahuddin provincial council, according to police.

City police chief Col. Hussein Ali said at least seven people were killed and more than 60 wounded in the blast, which left some 20 houses heavily damaged. A second car bomb was discovered about 100 yards from the blast site, but it did not explode, Ali said.