Iraqi officials say gunmen killed at least six people during a robbery in a trade market in the central city of Baquba on Saturday.
Authorities say the attackers entered two money exchange offices and shot people in each. The gunmen robbed the shops before fleeing.
Investigators say as security forces arrived at the scene, a car bomb exploded, wounding some police and civilians.
Iraqi authorities have blamed similar attacks on militant groups like al-Qaida seeking money to fund their activities.
There has been an upsurge of violence in Iraq in recent weeks, with bombings and the assassination of government workers and security force leaders.
On Thursday, a suicide car bomber killed more than 20 people in Hilla, a mostly Shi'ite city south of Baghdad. The attacker rammed a vehicle into a police station entrance as officers were changing shifts.