A car bomb killed at least 12 people and injured 42 others on Monday in Ameen, a Shi'ite district in eastern Baghdad, police and medical sources said.
No group immediately claimed responsibility for the attack, but Shi'ite areas are often targeted by Sunni Muslim militants from the Islamic State group.
The government is trying to dislodge the insurgents from large swathes of the country's north and west, but advances have been slow, particularly in the western province of Anbar.
The capital has witnessed a wave of kidnappings and attacks on government officials and civilians.
Earlier in the day, gunmen shot and killed a local official along with his son and nephew in the town of Tarmiya, about 25 km (15 miles) north of Baghdad, police and medics said.
The government has been struggling to rein in Shi'ite militias, seen as critical forces against Islamic State, or control criminal gangs carrying out contract killings, kidnappings and extortions.