Doctors at the capital's Al-Yarmuk hospital gave a casualty toll of five dead and 14 wounded.
Two suicide bombers blew themselves up near Abu al-Fadhel al-Abbas mosque in the Al-Turath district, a police officer told AFP, on condition of anonymity.
There was no immediate claim of responsiblity.
Eight people were killed in a suicide bombing at a market in eastern Baghdad on May 9, while two others died in a similar attack in late June, both also targeting Shiites.
Iraq in 2017 declared victory over Islamic State group jihadists after a gruelling months-long campaign to dismantle their self-declared "caliphate".
But sleeper cells of the Sunni extremist group have remained active, attacking civilians and security forces across the Shiite-majority country.