Police say the blast late Saturday struck near the gate of the Khalid bin al-Walid mosque in the capital's southern Dora neighborhood. A hospital official confirmed the casualty toll.
The officials spoke on condition of anonymity because they weren't authorized to release the information to journalists.
The bombing is the latest in a string of attacks that have rocked Iraq since the holy month of Ramadan began earlier in the week. They are part of a months-long spike in violence that has claimed more than 2,600 lives since the start of April.