The blast went off near a popular restaurant in the Mansur district, some 500 meters from an Iraqi army checkpoint.
Earlier on September 12, Iraqi state-run television reported that insurgents killed seven people and wounded others in an overnight attack on a Shi’ite mosque south of Ba’qubah.
Reports say the attackers first fired mortar rounds before raiding the mosque in Bani Saad, which is about 20 kilometers south of Ba’qubah.
The mosque was heavily damaged in the attack.
No further details were immediately available.