Baghdad, Iraq (CNN) -- Three siblings were among four killed when a car bomb exploded in eastern Baghdad on Thursday evening, police said.
The bomb was attached to a car belonging to Anmar Taha Ridha. Three of his children died in the blast and he and his wife were wounded. A fourth person in another car was killed and two others were wounded.
Earlier, a bomb blast on a busy street in the northern outskirts of Baghdad killed a police officer and wounded three other people, police said.
In the central city, mortar rounds hit the area known as the Green Zone, which houses government offices as well as the U.S. and British embassies, police said. There were no reports of casualties.
It was the latest in a series of attacks on the Green Zone this week. Mortar rounds fell in the heavily fortified area on Sunday and Monday.
Violence in Iraq has waned since the height of the insurgency in 2006 and 2007 but recent months have seen a spike in attacks amid political uncertainty -- the national elections remain inconclusive more than six months after they were held.
Iraqi politicians have been unable to form a government, and officials have expressed concerns that insurgents would take advantage of the political vacuum to try to reignite the sectarian bloodshed that gripped Iraq for years.
In July, nearly 400 Iraqis were killed, the highest monthly toll since May 2008. In August, violence killed 295 Iraqis and wounded 508 others. September has also been bloody.
Security is completely under Iraqi control as the last U.S. combat troops left the country this summer. About 50,000 U.S. troops remain, but in an advisory role.