Diyala provincial police reported that unidentified gunmen had attacked the house of the police chief in Baqouba, northeast of Baghdad, killing his wife, two brothers and 11 guards.
The attackers also abducted two sons and a daughter of police chief Col. Ali Dilayan al-Jorani, police said. The chief, head of central Baqouba's Balda police station, wasn't at home at the time, they said.
The children were described as young men and a young woman, but their ages weren't immediately available.
The two slain brothers were serving as guards at the house, in Kanaan town northwest of the city of Baqouba, which is 60 kilometers (35 miles) northeast of Baghdad.
The bodies of some guards, many of whom were also al-Jorani relatives, were found on a nearby road, apparently after being seized at the house, police said.
Diyala province, and particularly Baqouba, has been torn by violence in recent weeks as al- Qaida in Iraq and affiliated groups have battled Iraqi security forces, the U.S. military and some local insurgent groups that have turned against al-Qaida.
Later in the morning in southern Iraq, a parked minibus exploded at a bus terminal in the town of Qurna, and a hospital director said at least 16 people were killed and 32 wounded.
A witness, taxi driver Salim Abdul-Hussein, 35, said the blast damaged the terminal and many cars and surrounding shops, striking an area crowded each morning with farmers coming to town to shop and sell their produce and animals in Qurna, 375 kilometers (225 miles) south of Baghdad.
Maj. Gen. Mohammed Hammadi, police chief in Basra, the provincial capital 100 kilometers (60 miles) to the south, said a minibus loaded with rockets, ammunition, C4 explosives and benzene blew up and caused a nearby car to explode in flames - leading to an early report of two car bombs.
Police cordoned off the area and arrested two Egyptian suspects, he said.
Hammadi said eight people were killed and 28 wounded. Another police source, speaking on condition of anonymity because he was not authorized to deal with the press, said 15 people were killed. At Qurna hospital, director Ali Qassim told The Associated Press by telephone the hospital had received 16 bodies from the explosions and 32 wounded.
In other violence, unknown gunmen speeding by in the northern city of Kirkuk shot and killed a soldier, Adnan Mahmoud, as he drove with his 2-year-old daughter around 6:30 a.m. Friday. The child also was killed, said police Capt. Jassim Abdullah.
In Baghdad, U.S. Army artillery fired at least nine rounds Friday morning into a Sunni Muslim-dominated farming area in the city's southwestern sections of Arab Jibor and Albu Aitha, police reported. A police officer, who asked anonymity as he was not authorized to talk to media, said the shelling targeted "selective areas" where Sunni militants were active.