Interior Ministry spokesman, Saad Maan, said on state television on Thursday that security forces had started securing the area.
Sources told Al Jazeera that the attackers targeted the Kadhimiya prison in an attempted breakout.
A mortar round landed in the district, the sources said, adding that gunfire was also heard.
Bombs hit the capital on a near-daily basis but coordinated attacks of this scale have been rare in the last several weeks.
Mortar rounds have a short range compared to rockets, indicating the assailants fired from near the districts.
Interior Ministry spokesman Saad Maan said on state television that "the security forces are securing the area."
He said two "terrorists" had been arrested in Kadhimiya.
The Islamic State in Iraq and the Levant, an al-Qaeda offshoot that seized large parts of northern Iraq last month, has claimed several suicide bombings in the capital.